Touch Sensitive Processing Apparatus, System and Operating Method Thereof for Receiving Electrical signals Carrying Pressure Information

ABSTRACT

The present invention provides a touch sensitive processing apparatus for receiving electrical signals carrying pressure information transmitted from a first stylus, comprising: a sensing circuit, configured for receiving the electrical signals via electrodes of a touch panel; and a processor, coupled to the sensing circuit, configured for: despreading a first preamble code of the received electrical signals in accordance with a pseudo-random number (PN) code in a first time period; despreading a second preamble code of the received electrical signals in accordance with the PN code in a second time period; and calculating the pressure information according to a first signal strength ratio of a first part of the received electrical signal and a second part of the received electrical signal, wherein the first part comprises the first preamble code and the second part comprises the second preamble code.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part application claims benefitsof a U.S. patent application Ser. No. 15/184,286 and a U.S. patentapplication Ser. No. 15,788,051, filed on Oct. 19, 2017, which is acontinuation application of U.S. patent application Ser. No. 14/537,082,filed on Nov. 10, 2014 and issued as U.S. Pat. No. 9,851,816, whichclaims priorities under 35 U.S.C 119 to U.S. provisional patentapplication, 61/902,137, filed on Nov. 8, 2013, U.S. provisional patentapplication, 61/945,397, filed on Feb. 27, 2014, U.S. provisional patentapplication, 61/992,340, filed on May 13, 2014, and U.S. provisionalpatent application, 62/055,995, filed on Sep. 26, 2014. The U.S. patentSer. No. 15/184,286 is filed on Jun. 16, 2016, which claims priority toa U.S. provisional patent application No. 62/180,272, filed on Jun. 16,2015 and a Taiwan patent application No. 104144644, filed on Dec. 31,2015, the disclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to transmitter, and more particularly, totransmitter which is able to transmit an electric signal preciselyrepresenting a pressure on the transmitter.

2. Description of the Prior Art

Touch panel or touch sensitive screen is important human machineinterface in modern age. In addition to detecting approximation or touchof human body, touch panel is also used for detecting approximation ortouch of stylus or tip of stylus such that user is able to preciselycontrol a trace painted by a touching tip.

Stylus may actively emit electrical signals via its tip. In this presentapplication, it is called active stylus. When the tip approximating ortouching a touch panel, electromagnetic response of the electric signaloccurs to electrodes of the touch panel. By detecting theelectromagnetic response corresponding to the electric signal, thestylus approximating or touching the sensing electrodes could bedetected. Therefore a position of the tip relative to the touch panelcould be concluded accordingly.

Hence, it is required to have active stylus transmitting electricalsignals which precisely reflect the pressure level.

From the above it is clear that prior art still has shortcomings. Inorder to solve these problems, efforts have long been made in vain,while ordinary products and methods offering no appropriate structuresand methods. Thus, there is a need in the industry for a novel techniquethat solves these problems.

SUMMARY OF THE INVENTION

One object of the present invention is to provide a stylus which is ableto transmit electric signals precisely representing a pressure on thestylus.

One object of the present invention is to provide a stylus fortransmitting electrical signals carrying pressure information,comprising: a first component with variable impedance reflecting apressure, wherein the first component is configured for receiving firstsignals encoded by a first pseudo-random number (PN) code; a secondcomponent with fixed impedance, wherein the second component isconfigured for receiving second signals encoded by a second PN code; anda conductive tip section configured for: receiving, simultaneously, thefirst signals from the first component and the second signals from thesecond component; and transmitting electrical signals which is composedof the first signals and the second signals, wherein the first PN codeis orthogonal to the second PN code.

In one embodiment, in order to provide the first PN code and the secondPN code onboard the stylus, the stylus further comprises a controller,configured for: generating the first signals according to the first PNcode; generating the second signals according the second PN code;transmitting the first signals to the first component; and transmittingthe second signals to the second component.

In one embodiment, in order to transmit status of onboard sensor of thestylus, the stylus further comprises: at least one onboard sensorcoupled to the controller. The controller is further configured for:generating data codes according to status of the at least one onboardsensor; generating first data codes according to the data codes and thefirst PN code; and transmitting the first data codes to the firstcomponent. The first component is further configured for receiving thefirst data codes from the controller. The conductive tip section isfurther configured for: receiving the first data codes from the firstcomponent; and transmitting the first data codes.

In one embodiment, in order to transmit status of onboard sensor of thestylus, the stylus further comprises: at least one onboard sensorcoupled to the controller. The controller is further configured for:generating data codes according to status of the at least one onboardsensor; generating second data codes according to the data codes and thesecond PN code; and transmitting the second data codes to the secondcomponent. The second component is further configured for receiving thesecond data codes from the controller. The conductive tip section isfurther configured for: receiving the second data codes from the secondcomponent; and transmitting the second data codes.

In one embodiment, in order to synchronize with receiving procedure of atouch sensitive processing apparatus of a touch panel, the controller isfurther configured for: receiving a synchronization signal from anelectronic device; and after the synchronization signal is received,executing the generating steps and the transmitting steps.

In one embodiment, in order to synchronize with receiving procedure ofthe touch sensitive processing apparatus of the touch panel where thestylus touches or approximates, the controller is coupled to theconductive tip section for receiving the synchronization signal which isbeing transmitted from electrodes of a touch panel of the electronicdevice.

In one embodiment, in order to prevent conflicts of PN codes whenmultiple styli operate with one touch panel, the stylus furthercomprises a human-machine interface for user's input of PN codes,wherein the controller is further configured for receiving a settinginstruction from the human-machine interface for designating a set ofthe first PN code and the second PN code.

In one embodiment, in order to provide PN code setting information touser, the stylus further comprises at least one of following devicecoupled to the controller for indicating a set of the first PN code andthe second PN code: a visual indicator; and an audio indicator.

In one embodiment, in order to provide a wire connection between thecorded or tethered stylus and a touch sensitive processing apparatus,the stylus further comprises: a first signal circuit, coupled to thefirst component and a touch sensitive processing apparatus, configuredfor propagating the first signals from the touch sensitive processingapparatus to the first component; and a second signal circuit, coupledto the second component and the touch sensitive processing apparatus,configured for propagating the second signals from the touch sensitiveprocessing apparatus to the second component.

In one embodiment, in order to provide a switch status to a touchsensitive processing apparatus, the stylus further comprises a thirdswitch configured for receiving the first signals; and a third componentwith fixed impedance, coupled to the third switch and the conductive tipsection, wherein the third switch is selectively being opened or closed,the first signals are propagated through the third switch and the thirdcomponent to the conductive tip section when the third switch is beingclosed.

In one embodiment, in order to provide a switch status to a touchsensitive processing apparatus, the stylus further comprises a fourthswitch configured for receiving the second signals; and a fourthcomponent with fixed impedance, coupled to the third switch and theconductive tip section, wherein the fourth switch is selectively beingopened or closed, the second signals are propagated through the fourthswitch and the fourth component to the conductive tip section when thefourth switch is being closed.

One object of the present invention is to provide a method fortransmitting electrical signals carrying pressure information from astylus, comprising: receiving, by a first component with variableimpedance reflecting a pressure, first signals encoded by a first PNcode; receiving, by a second component with fixed impedance, secondsignals encoded by a second PN code; receiving, simultaneously, thefirst signals from the first component and the second signals from thesecond component by a conductive tip section; and transmittingelectrical signals which is composed of the first signals and the secondsignals by the conductive tip section, wherein the first PN code isorthogonal to the second PN code.

In one embodiment, in order to provide the first PN code and the secondPN code onboard the stylus, the method further comprises: generating thefirst signals according to the first PN code; generating the secondsignals according the second PN code; transmitting the first signals tothe first component; and transmitting the second signals to the secondcomponent.

In one embodiment, in order to transmit status of onboard sensor of thestylus, the method further comprises: generating data codes according tostatus of at least one onboard sensor; generating first data codesaccording to the data codes and the first PN code; transmitting thefirst data codes to the first component; transmitting, by the firstcomponent, the first data codes to the conductive tip section; andtransmitting, by the conductive tip section, the first data codes.

In one embodiment, in order to transmit status of onboard sensor of thestylus, the method further comprises: generating data codes according tostatus of at least one onboard sensor; generating second data codesaccording to the data codes and the second PN code; transmitting thesecond data codes to the second component; transmitting, by the secondcomponent, the second data codes to the conductive tip section; andtransmitting, by the conductive tip section, the first data codes.

In one embodiment, in order to synchronize with receiving procedure of atouch sensitive processing apparatus of a touch panel, the method isfurther configured for: receiving a synchronization signal from anelectronic device; and after the synchronization signal is received,executing the generating steps and the transmitting steps.

In one embodiment, in order to synchronize with receiving procedure ofthe touch sensitive processing apparatus of the touch panel where thestylus touches or approximates, the synchronization signal which isbeing transmitted from electrodes of a touch panel of the electronicdevice to the conductive tip section.

In one embodiment, in order to prevent conflicts of PN codes whenmultiple styli operate with one touch panel, the method furthercomprises: receiving a setting instruction from a human-machineinterface of the stylus for designating a set of the first PN code andthe second PN code.

In one embodiment, in order to provide PN code setting information touser, the method further comprises at least one of following steps:having a visual indicator of the stylus indicating a set of the first PNcode and the second PN code; and having an audio indicator of the stylusindicating the set of the first PN code and the second PN code.

In one embodiment, in order to provide a wire connection between thecorded or tethered stylus and a touch sensitive processing apparatus,the method further comprises: receiving, by a first signal circuit, thefirst signals from a touch sensitive processing apparatus; propagating,by the first signal circuit, the first signals to the first component;receiving, by a second signal circuit, the second signals from the touchsensitive processing apparatus; and propagating, by the second signalcircuit, the second signals to the second component.

In one embodiment, in order to provide a switch status to a touchsensitive processing apparatus, the method further comprises:selectively receiving, by a third component with fixed impedance, thefirst signals; and selectively transmitting, by the third component, thefirst signals to the conductive tip section.

In one embodiment, in order to provide a switch status to a touchsensitive processing apparatus, the method further comprises:selectively receiving, by a fourth component with fixed impedance, thesecond signals; and selectively transmitting, by the fourth component,the second signals to the conductive tip section.

One object of the present invention is to provide a touch sensitiveprocessing apparatus for receiving electrical signals carrying pressureinformation transmitted from a first stylus, comprising: a sensingcircuit, configured for receiving the electrical signals via electrodesof a touch panel; and a processor, coupled to the sensing circuit,configured for: despreading a first preamble code of the receivedelectrical signals in accordance with a first pseudo-random number (PN)code; despreading a second preamble code of the received electricalsignals in accordance with a second PN code; and calculating thepressure information according to a first signal strength ratio of afirst part of the received electrical signal and a second part of thereceived electrical signal, wherein the first part comprises the firstpreamble code and the second part comprises the second preamble code,wherein the first PN code is orthogonal to the second PN code.

In one embodiment, in order to trigger the stylus for transmittingelectrical signals synchronously, the touch sensitive processingapparatus further comprises a driving circuit, coupled to the electrodesof the touch panel, wherein the processor is further configured forhaving the driving circuit to transmit a beacon signal via theelectrodes of the touch panel before the receiving step is beingexecuted.

In one embodiment, in order to receive status of sensor onboard thestylus, the processor is further configured for: decoding first datacodes of the received electrical signal in accordance with the first PNcode, wherein the first data codes represents status of at least oneonboard sensor of the first stylus.

In one embodiment, in order to receive status of sensor onboard thestylus, the processor is further configured for: decoding second datacodes of the received electrical signal in accordance with the second PNcode, wherein the second data codes represents status of at least oneonboard sensor of the first stylus.

In one embodiment, in order to correctly receive status of sensoronboard the stylus, the processor is further configured for: decodingfirst data codes of the received electrical signal in accordance withthe first PN code; decoding second data codes of the received electricalsignal in accordance with the second PN code; and determining data codesif the first data codes and the second data codes are the same, whereinthe data codes represents status of at least one onboard sensor of thefirst stylus.

In one embodiment, in order to receive more smooth and averaged pressureinformation in a longer transmission, the first part further comprisesthe first data codes and the second part further comprises the seconddata codes.

In one embodiment, in order to synchronize with the transmission of thestylus more quickly, the processor is further configured for: couplingat least two of second electrodes of the touch panel as asynchronization channel, wherein the despreading steps of the firstpreamble code and the second preamble code are being executed on thereceived electrical signals of the synchronization channel to retrieve afirst synchronization information and a second synchronizationinformation, respectively, wherein the second electrodes are arranged inparallel to each other.

In one embodiment, in order to correctly and quickly receive status ofsensor onboard the stylus by utilizing synchronization information, theprocessor is further configured for: decoding first data codes of thereceived electrical signal from at least one of first electrodes of thetouch panel in accordance with the first PN code and the firstsynchronization information; decoding second data codes of the receivedelectrical signal from at least one of the first electrodes of the touchpanel in accordance with the second PN code and the secondsynchronization information; and determining data codes if the firstdata codes and the second data codes are the same, wherein the datacodes represents status of at least one onboard sensor of the firststylus, wherein the first electrodes are arranged in parallel to eachother, and the first electrodes intersect with the second electrodes.

In one embodiment, in order to concurrently receive electrical signalsfrom multiple styli, the processor is further configured for:despreading a third preamble code of the received electrical signals inaccordance with a third PN code; despreading a fourth preamble code ofthe received electrical signals in accordance with a fourth PN code; andcalculating a pressure information of a second stylus according to asecond signal strength ratio of a third part of the received electricalsignal and a fourth part of the received electrical signal, wherein thethird part comprises the third preamble code and the fourth partcomprises the fourth preamble code, wherein the first PN code, thesecond PN code, the third PN code and the fourth PN code are orthogonalto each other.

In one embodiment, in order to provide a wire connection between acorded or tethered stylus and the touch sensitive processing apparatus,the touch sensitive processing apparatus further comprises: a stylusinterface, coupled to a first signal circuit and a second signal circuitof the first stylus, wherein the processor, coupled to the stylusinterface, is further configured for: generating the first preamble codein accordance with the first PN code; generating the second preamblecode in accordance with the second PN code; and transmitting the firstpreamble code and the second preamble code to the first signal circuitand the second signal circuit via the stylus interface, respectively.

In one embodiment, in order to receive status of a switch of the stylus,the processor is further configured for: calculating a switch status ofthe first stylus according to the first signal strength ratio of thefirst part of the received electrical signal and the second part of thereceived electrical signal.

In one embodiment, in order to concurrently connect with multiple cordedor tethered styli, the stylus interface is further coupled to a thirdsignal circuit and a fourth signal circuit of a second stylus. Theprocessor, coupled to the stylus interface, is further configured for:generating a third preamble code in accordance with a third PN code;generating a fourth preamble code in accordance with a fourth PN code;and transmitting the third preamble code and the fourth preamble code tothe third signal circuit and the fourth signal circuit via the stylusinterface, respectively, wherein the first PN code, the second PN code,the third PN code and the fourth PN code are orthogonal to each other.

One object of the present invention is to provide a method for receivingelectrical signals carrying pressure information transmitted from afirst stylus, comprising: receiving the electrical signals viaelectrodes of a touch panel; despreading a first preamble code of thereceived electrical signals in accordance with a first PN code;despreading a second preamble code of the received electrical signals inaccordance with a second PN code; and calculating the pressureinformation according to a first signal strength ratio of a first partof the received electrical signal and a second part of the receivedelectrical signal, wherein the first part comprises the first preamblecode and the second part comprises the second preamble code, wherein thefirst PN code is orthogonal to the second PN code.

In one embodiment, in order to trigger the stylus for transmittingelectrical signals synchronously, the method further comprises:transmitting a beacon signal via the electrodes of the touch panelbefore the receiving step is being executed.

In one embodiment, in order to receive status of sensor onboard thestylus, the method further comprises: decoding first data codes of thereceived electrical signal in accordance with the first PN code, whereinthe first data codes represents status of at least one onboard sensor ofthe first stylus.

In one embodiment, in order to receive status of sensor onboard thestylus, the method further comprises: decoding second data codes of thereceived electrical signal in accordance with the second PN code,wherein the second data codes represents status of at least one onboardsensor of the first stylus.

In one embodiment, in order to correctly receive status of sensoronboard the stylus, the method further comprises: decoding first datacodes of the received electrical signal in accordance with the first PNcode; decoding second data codes of the received electrical signal inaccordance with the second PN code; and determining data codes if thefirst data codes and the second data codes are the same, wherein thedata codes represents status of at least one onboard sensor of the firststylus.

In one embodiment, in order to receive more smooth and averaged pressureinformation in a longer transmission, the first part further comprisesthe first data codes and the second part further comprises the seconddata codes.

In one embodiment, in order to synchronize with the transmission of thestylus more quickly, the method further comprises: coupling at least twoof second electrodes of the touch panel as a synchronization channel,wherein the despreading steps of the first preamble code and the secondpreamble code are being executed on the received electrical signals ofthe synchronization channel to retrieve a first synchronizationinformation and a second synchronization information, respectively,wherein the second electrodes are arranged in parallel to each other.

In one embodiment, in order to correctly and quickly receive status ofsensor onboard the stylus by utilizing synchronization information, themethod further comprises: decoding first data codes of the receivedelectrical signal from at least one of first electrodes of the touchpanel in accordance with the first PN code and the first synchronizationinformation; decoding second data codes of the received electricalsignal from at least one of the first electrodes of the touch panel inaccordance with the second PN code and the second synchronizationinformation; and determining data codes if the first data codes and thesecond data codes are the same, wherein the data codes represents statusof at least one onboard sensor of the first stylus, wherein the firstelectrodes are arranged in parallel to each other, and the firstelectrodes intersect with the second electrodes.

In one embodiment, in order to concurrently receive electrical signalsfrom multiple styli, the method further comprises: despreading a thirdpreamble code of the received electrical signals in accordance with athird PN code; despreading a fourth preamble code of the receivedelectrical signals in accordance with a fourth PN code; and calculatinga pressure information of a second stylus according to a second signalstrength ratio of a third part of the received electrical signal and afourth part of the received electrical signal, wherein the third partcomprises the third preamble code and the fourth part comprises thefourth preamble code, wherein the first PN code, the second PN code, thethird PN code and the fourth PN code are orthogonal to each other.

In one embodiment, in order to provide a wire connection between acorded or tethered stylus and the touch sensitive processing apparatus,the method further comprises: generating the first preamble code inaccordance with the first PN code; generating the second preamble codein accordance with the second PN code; and transmitting the firstpreamble code and the second preamble code to a first signal circuit anda second signal circuit of the first stylus, respectively.

In one embodiment, in order to receive status of a switch of the stylus,the method further comprises: calculating a switch status of the firststylus according to the first signal strength ratio of the first part ofthe received electrical signal and the second part of the receivedelectrical signal.

In one embodiment, in order to concurrently connect with multiple cordedor tethered styli, the method further comprises: generating a thirdpreamble code in accordance with a third PN code; generating a fourthpreamble code in accordance with a fourth PN code; and transmitting thethird preamble code and the fourth preamble code to a third signalcircuit and a fourth signal circuit of a second stylus, respectively,wherein the first PN code, the second PN code, the third PN code and thefourth PN code are orthogonal to each other.

One object of the present invention is to provide a touch system, whichcomprising: a touch panel; a first stylus; and a touch sensitiveprocessing apparatus for receiving electrical signals carrying pressureinformation transmitted from the first stylus. The touch sensitiveprocessing apparatus comprises: a sensing circuit, configured forreceiving the electrical signals via electrodes of the touch panel; anda processor, coupled to the sensing circuit, configured for: despreadinga first preamble code of the received electrical signals in accordancewith a first PN code; despreading a second preamble code of the receivedelectrical signals in accordance with a second PN code; and calculatingthe pressure information according to a first signal strength ratio of afirst part of the received electrical signal and a second part of thereceived electrical signal, wherein the first part comprises the firstpreamble code and the second part comprises the second preamble code,wherein the first PN code is orthogonal to the second PN code.

In one embodiment, the first stylus further comprises: a first componentwith variable impedance reflecting a pressure, wherein the firstcomponent is configured for receiving first signals encoded by the firstPN code; a second component with fixed impedance, wherein the secondcomponent is configured for receiving second signals encoded by thesecond PN code; and a conductive tip section configured for: receiving,simultaneously, the first signals from the first component and thesecond signals from the second component; and transmitting theelectrical signals which is composed of the first signals and the secondsignals.

One object of the present invention is to provide a stylus fortransmitting electrical signals carrying pressure information,comprising: a first component with variable impedance reflecting apressure, wherein the first component is configured for receiving firstsignals encoded by a pseudo-random number (PN) code in a first timeperiod; a second component with fixed impedance, wherein the secondcomponent is configured for receiving second signals encoded by the PNcode in a second time period; and a conductive tip section configuredfor: receiving the first signals from the first component in the firsttime period; receiving the second signals from the second component inthe second time period; transmitting electrical signals which iscomposed of the first signals in the first time period; and transmittingelectrical signals which is composed of the second signals in the secondtime period.

In one embodiment, in order to provide the PN code onboard the stylus,the stylus further comprises a controller, configured for: generatingthe first signals according to the PN code; generating the secondsignals according the PN code; transmitting the first signals to thefirst component; and transmitting the second signals to the secondcomponent.

In one embodiment, in order to transmit status of onboard sensor of thestylus, the stylus further comprises: at least one onboard sensorcoupled to the controller, wherein the controller is further configuredfor: generating data codes according to status of the at least oneonboard sensor; generating first data codes according to the data codesand the PN code; and transmitting the first data codes to the firstcomponent. The first component is further configured for receiving thefirst data codes from the controller in the first time period. Theconductive tip section is further configured for in the first timeperiod: receiving the first data codes from the first component; andtransmitting the first data codes.

In one embodiment, in order to transmit status of onboard sensor of thestylus, the stylus further comprises: at least one onboard sensorcoupled to the controller, wherein the controller is further configuredfor: generating data codes according to status of the at least oneonboard sensor; generating second data codes according to the data codesand the PN code; and transmitting the second data codes to the secondcomponent. The second component is further configured for receiving thesecond data codes from the controller in the second time period. Theconductive tip section is further configured for in the second timeperiod: receiving the second data codes from the second component; andtransmitting the second data codes.

In one embodiment, in order to synchronize with receiving procedure of atouch sensitive processing apparatus of a touch panel, the controller isfurther configured for: receiving a synchronization signal from anelectronic device; and after the synchronization signal is received,executing the generating steps and the transmitting steps.

In one embodiment, in order to synchronize with receiving procedure ofthe touch sensitive processing apparatus of the touch panel where thestylus touches or approximates, the controller is coupled to theconductive tip section for receiving the synchronization signal which isbeing transmitted from electrodes of a touch panel of the electronicdevice.

In one embodiment, in order to prevent conflicts of PN codes whenmultiple styli operate with one touch panel, the stylus furthercomprises a human-machine interface for user's input of PN codes,wherein the controller is further configured for receiving a settinginstruction from the human-machine interface for designating the PNcode.

In one embodiment, in order to provide PN code setting information touser, the stylus further comprises at least one of following devicecoupled to the controller for indicating the PN code: a visualindicator; and an audio indicator.

In one embodiment, in order to provide a wire connection between thecorded or tethered stylus and a touch sensitive processing apparatus,the stylus further comprises: a first signal circuit, coupled to thefirst component and a touch sensitive processing apparatus, configuredfor propagating the first signals from the touch sensitive processingapparatus to the first component; and a second signal circuit, coupledto the second component and the touch sensitive processing apparatus,configured for propagating the second signals from the touch sensitiveprocessing apparatus to the second component.

In order to provide a switch status to a touch sensitive processingapparatus, the stylus further comprises: a third switch configured forreceiving the first signals in the first time period; and a thirdcomponent with fixed impedance, coupled to the third switch and theconductive tip section, wherein the third switch is selectively beingopened or closed, the first signals are propagated through the thirdswitch and the third component to the conductive tip section when thethird switch is being closed.

In order to provide a switch status to a touch sensitive processingapparatus, the stylus further comprises: a fourth switch configured forreceiving the second signals in the second time period; and a fourthcomponent with fixed impedance, coupled to the third switch and theconductive tip section, wherein the fourth switch is selectively beingopened or closed, the second signals are propagated through the fourthswitch and the fourth component to the conductive tip section when thefourth switch is being closed.

One object of the present invention is to provide a method fortransmitting electrical signals carrying pressure information from astylus, comprising: receiving, by a first component with variableimpedance reflecting a pressure, first signals encoded by a PN code in afirst time period; receiving, by a second component with fixedimpedance, second signals encoded by the PN code in a second timeperiod; receiving the first signals from the first component by aconductive tip section in the first time period; receiving the secondsignals from the second component by the conductive tip section in thesecond time period; and transmitting electrical signals which iscomposed of the first signals in the first time period by the conductivetip section; and transmitting electrical signals which is composed ofthe second signals in the second time period by the conductive tipsection.

In one embodiment, in order to provide the PN code onboard the stylus,the method further comprises: generating the first signals according tothe PN code; generating the second signals according the PN code;transmitting the first signals to the first component; and transmittingthe second signals to the second component.

In one embodiment, in order to transmit status of onboard sensor of thestylus, the method further comprises: generating data codes according tostatus of at least one onboard sensor; generating first data codesaccording to the data codes and the PN code; transmitting the first datacodes to the first component; transmitting, by the first component, thefirst data codes to the conductive tip section; and transmitting, by theconductive tip section, the first data codes.

In one embodiment, in order to transmit status of onboard sensor of thestylus, the method further comprises: generating data codes according tostatus of at least one onboard sensor; generating second data codesaccording to the data codes and the PN code; and transmitting the seconddata codes to the second component; transmitting, by the secondcomponent, the second data codes to the conductive tip section; andtransmitting, by the conductive tip section, the second data codes.

In one embodiment, in order to synchronize with receiving procedure of atouch sensitive processing apparatus of a touch panel, the methodfurther comprises: receiving a synchronization signal from an electronicdevice; and after the synchronization signal is received, executing thegenerating steps and the transmitting steps.

In one embodiment, in order to synchronize with receiving procedure ofthe touch sensitive processing apparatus of the touch panel where thestylus touches or approximates, wherein the synchronization signal whichis being transmitted from electrodes of a touch panel of the electronicdevice to the conductive tip section.

In one embodiment, in order to prevent conflicts of PN codes whenmultiple styli operate with one touch panel, the method furthercomprises: receiving a setting instruction from a human-machineinterface of the stylus for designating the PN code.

In one embodiment, in order to provide PN code setting information touser, the method further comprises at least one of following steps:having a visual indicator of the stylus indicating the PN code; andhaving an audio indicator of the stylus indicating the PN code.

In one embodiment, in order to provide a wire connection between thecorded or tethered stylus and a touch sensitive processing apparatus,the method futher comprises: receiving, by a first signal circuit, thefirst signals from a touch sensitive processing apparatus; propagating,by the first signal circuit, the first signals to the first component;receiving, by a second signal circuit, the second signals from the touchsensitive processing apparatus; and propagating, by the second signalcircuit, the second signals to the second component.

In one embodiment, in order to provide a switch status to a touchsensitive processing apparatus, the method further comprises:selectively receiving, by a third component with fixed impedance, thefirst signals; and selectively transmitting, by the third component, thefirst signals to the conductive tip section.

In one embodiment, in order to provide a switch status to a touchsensitive processing apparatus, the method further comprises:selectively receiving, by a fourth component with fixed impedance, thesecond signals; and selectively transmitting, by the fourth component,the second signals to the conductive tip section.

One object of the present invention is to provide a touch sensitiveprocessing apparatus for receiving electrical signals carrying pressureinformation transmitted from a first stylus, comprising: a sensingcircuit, configured for receiving the electrical signals via electrodesof a touch panel; and a processor, coupled to the sensing circuit,configured for: despreading a first preamble code of the receivedelectrical signals in accordance with a pseudo-random number (PN) codein a first time period; despreading a second preamble code of thereceived electrical signals in accordance with the PN code in a secondtime period; and calculating the pressure information according to afirst signal strength ratio of a first part of the received electricalsignal and a second part of the received electrical signal, wherein thefirst part comprises the first preamble code and the second partcomprises the second preamble code.

In one embodiment, in order to trigger the stylus for transmittingelectrical signals synchronously, the touch sensitive apparatus furthercomprises: a driving circuit, coupled to the electrodes of the touchpanel, wherein the processor is further configured for having thedriving circuit to transmit a beacon signal via the electrodes of thetouch panel before the receiving steps are being executed.

In one embodiment, in order to receive status of sensor onboard thestylus, the processor is further configured for: decoding first datacodes of the electrical signal received in the first time period inaccordance with the PN code, wherein the data codes represents status ofat least one onboard sensor of the first stylus.

In one embodiment, in order to receive status of sensor onboard thestylus, the processor is further configured for: decoding second datacodes of the electrical signal received in the second time period inaccordance with the PN code, wherein the data codes represents status ofat least one onboard sensor of the first stylus.

In one embodiment, in order to correctly receive status of sensoronboard the stylus, the processor is further configured for: decodingfirst data codes of the electrical signal received in the first timeperiod in accordance with the PN code; decoding second data codes of theelectrical signal received in the second time period in accordance withthe PN code; and determining data codes if the first data codes and thesecond data codes are the same, wherein the data codes represents statusof at least one onboard sensor of the first stylus.

In one embodiment, in order to receive more smooth and averaged pressureinformation in a longer transmission, the first part further comprisesthe first data codes and the second part further comprises the seconddata codes.

In one embodiment, in order to synchronize with the transmission of thestylus more quickly, the processor is further configured for: couplingat least two of second electrodes of the touch panel as asynchronization channel, wherein the despreading steps of the firstpreamble code and the second preamble code are being executed on thereceived electrical signals of the synchronization channel to retrieve afirst synchronization information and a second synchronizationinformation, respectively, wherein the second electrodes are arranged inparallel to each other.

In one embodiment, in order to correctly and quickly receive status ofsensor onboard the stylus by utilizing synchronization information, theprocessor is further configured for: decoding first data codes of thereceived electrical signal from at least one of first electrodes of thetouch panel in accordance with the PN code and the first synchronizationinformation; decoding second data codes of the received electricalsignal from at least one of the first electrodes of the touch panel inaccordance with the PN code and the second synchronization information;and determining data codes if the first data codes and the second datacodes are the same, wherein the data codes represents status of at leastone onboard sensor of the first stylus, wherein the first electrodes arearranged in parallel to each other, and the first electrodes intersectwith the second electrodes.

In one embodiment, in order to receive electrical signals from multiplestyli, the processor is further configured for: despreading a thirdpreamble code of the electrical signals received in a third time periodin accordance with a second PN code; despreading a fourth preamble codeof the electrical signals received in a fourth time period in accordancewith the second PN code; and calculating a pressure information of asecond stylus according to a second signal strength ratio of a thirdpart of the received electrical signal and a fourth part of the receivedelectrical signal, wherein the third part comprises the third preamblecode and the fourth part comprises the fourth preamble code, wherein thePN code and the second PN code are orthogonal to each other, whereinpart of the third time period is overlapped with part of the first timeperiod or part of the second time period.

In one embodiment, in order to provide a wire connection between acorded or tethered stylus and the touch sensitive processing apparatus,the touch sensitive processing apparatus further comprises: a stylusinterface, coupled to a first signal circuit and a second signal circuitof the first stylus, wherein the processor, coupled to the stylusinterface, is further configured for: generating the first preamble codein accordance with the PN code; generating the second preamble code inaccordance with the PN code; transmitting the first preamble code to thefirst signal circuit via the stylus interface in the first time period;and transmitting the second preamble code to the second signal circuitvia the stylus interface in the second time period.

In one embodiment, in order to receive status of a switch of the stylus,the processor is further configured for: calculating a switch status ofthe first stylus according to the first signal strength ratio of thefirst part of the received electrical signal and the second part of thereceived electrical signal.

In one embodiment, in order to concurrently connect with multipl styli,the stylus interface is further coupled to a third signal circuit and afourth signal circuit of a second stylus. The processor, coupled to thestylus interface, is further configured for: generating a third preamblecode in accordance with a second PN code in a third time period;generating a fourth preamble code in accordance with the second PN codein a fourth time period; transmitting the third preamble code to thethird signal circuit in the third time period via the stylus interface;and transmitting the fourth preamble code to the fourth signal circuitin the fourth time period via the stylus interface, respectively,wherein the PN code and the second PN code are orthogonal to each other,wherein part of the third time period is overlapped with part of thefirst time period or part of the second time period.

One object of the present invention is to provide a method for receivingelectrical signals carrying pressure information transmitted from afirst stylus, comprising: receiving the electrical signals viaelectrodes of a touch panel; despreading a first preamble code of theelectrical signals received in a first time period in accordance with aPN code; despreading a second preamble code of the electrical signalsreceived in a second time period in accordance with the PN code; andcalculating the pressure information according to a first signalstrength ratio of a first part of the received electrical signal and asecond part of the received electrical signal, wherein the first partcomprises the first preamble code and the second part comprises thesecond preamble code.

In one embodiment, in order to trigger the stylus for transmittingelectrical signals synchronously, the method further comprisestransmitting a beacon signal via the electrodes of the touch panelbefore the receiving step is being executed.

In one embodiment, in order to receive status of sensor onboard thestylus, the method further comprises: decoding first data codes of theelectrical signal received in the first time period in accordance withthe PN code, wherein the first data codes represents status of at leastone onboard sensor of the first stylus.

In one embodiment, in order to receive status of sensor onboard thestylus, the method further comprises: decoding second data codes of theelectrical signal received in the second time period in accordance withthe PN code, wherein the second data codes represents status of at leastone onboard sensor of the first stylus.

In one embodiment, in order to correctly receive status of sensoronboard the stylus, the method further comprises: decoding first datacodes of the electrical signal received in the first time period inaccordance with the PN code; decoding second data codes of theelectrical signal received in the second time period in accordance withthe PN code; and determining data codes if the first data codes and thesecond data codes are the same, wherein the data codes represents statusof at least one onboard sensor of the first stylus.

In one embodiment, in order to receive more smooth and averaged pressureinformation in a longer transmission, the first part further comprisesthe first data codes and the second part further comprises the seconddata codes.

In one embodiment, in order to synchronize with the transmission of thestylus more quickly, the method further comprises: coupling at least twoof second electrodes of the touch panel as a synchronization channel,wherein the despreading steps of the first preamble code and the secondpreamble code are being executed on the received electrical signals ofthe synchronization channel to retrieve a first synchronizationinformation and a second synchronization information, respectively,wherein the second electrodes are arranged in parallel to each other.

In one embodiment, in order to correctly and quickly receive status ofsensor onboard the stylus by utilizing synchronization information, themethod further comprises: decoding first data codes of the receivedelectrical signal from at least one of first electrodes of the touchpanel in accordance with the PN code and the first synchronizationinformation; decoding second data codes of the received electricalsignal from at least one of the first electrodes of the touch panel inaccordance with the PN code and the second synchronization information;and determining data codes if the first data codes and the second datacodes are the same, wherein the data codes represents status of at leastone onboard sensor of the first stylus, wherein the first electrodes arearranged in parallel to each other, and the first electrodes intersectwith the second electrodes.

In one embodiment, in order to concurrently receive electrical signalsfrom multiple styli, the method further comprises: despreading a thirdpreamble code of the electrical signals received in a third time periodin accordance with a second PN code; despreading a fourth preamble codeof the electrical signals received in a fourth time period in accordancewith the second PN code; and calculating a pressure information of asecond stylus according to a second signal strength ratio of a thirdpart of the received electrical signal and a fourth part of the receivedelectrical signal, wherein the third part comprises the third preamblecode and the fourth part comprises the fourth preamble code, wherein thePN code and the second PN code are orthogonal to each other, whereinpart of the third time period is overlapped with part of the first timeperiod or part of the second time period.

In one embodiment, in order to provide a wire connection between acorded or tethered stylus and the touch sensitive processing apparatus,the method further comprises: generating the first preamble code inaccordance with the PN code in the first time period; generating thesecond preamble code in accordance with the PN code in the second timeperiod; transmitting the first preamble code to a first signal circuitof the first stylus in the first time period; and transmitting thesecond preamble code to a second signal circuit of the first stylus inthe second time period.

In one embodiment, in order to receive status of a switch of the stylus,the method further comprises: calculating a switch status of the firststylus according to the first signal strength ratio of the first part ofthe received electrical signal and the second part of the receivedelectrical signal.

In one embodiment, in order to concurrently connect with multiple cordedor tethered styli, the method further comprises: generating a thirdpreamble code in accordance with a second PN code in a third timeperiod; generating a fourth preamble code in accordance with the secondPN code in a fourth time period; transmitting the third preamble code toa third signal circuit of a second stylus in the third time period; andtransmitting the fourth preamble code to a fourth signal circuit of thesecond stylus in the fourth time period, wherein the PN code and thesecond PN code are orthogonal to each other, wherein part of the thirdtime period is overlapped with part of the first time period or part ofthe second time period.

One object of the present invention is to provide a touch systemcomprising: a touch panel; a first stylus; and a touch sensitiveprocessing apparatus. The touch sensitive processing apparatus forreceiving electrical signals carrying pressure information transmittedfrom the first stylus, comprising: a sensing circuit, configured forreceiving the electrical signals via electrodes of the touch panel; anda processor, coupled to the sensing circuit, configured for: despreadinga first preamble code of the received electrical signals in accordancewith a PN code in a first time period; despreading a second preamblecode of the received electrical signals in accordance with the PN codein a second time period; and calculating the pressure informationaccording to a first signal strength ratio of a first part of thereceived electrical signal and a second part of the received electricalsignal, wherein the first part comprises the first preamble code and thesecond part comprises the second preamble code.

In one embodiment, the first stylus comprising: a first component withvariable impedance reflecting a pressure, wherein the first component isconfigured for receiving first signals encoded by the PN code in thefirst time period; a second component with fixed impedance, wherein thesecond component is configured for receiving second signals encoded bythe PN code in the second time period; and a conductive tip sectionconfigured for: receiving the first signals from the first component inthe first time period; receiving the second signals from the secondcomponent in the second time period; transmitting electrical signalswhich is composed of the first signals in the first time period; andtransmitting electrical signals which is composed of the second signalsin the second time period.

The above description is only an outline of the technical schemes of thepresent invention. Preferred embodiments of the present invention areprovided below in conjunction with the attached drawings to enable onewith ordinary skill in the art to better understand said and otherobjectives, features and advantages of the present invention and to makethe present invention accordingly.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention can be more fully understood by reading thefollowing detailed description of the preferred embodiments, withreference made to the accompanying drawings, wherein:

FIG. 1 illustrates a block diagram of a touch sensitive system 100 inaccordance with an embodiment of the present invention.

FIG. 2 depicts a block diagram of a transmitter 110 in accordance withan embodiment of the present invention.

FIG. 3 shows a block diagram of a transmitter 110 in accordance with anembodiment of the present invention.

FIG. 4A depicts a block diagram of a transmitter 110 in accordance withan embodiment of the present invention.

FIG. 4B depicts a block diagram of a transmitter 110 in accordance withan embodiment of the present invention.

FIG. 5 depicts a block diagram of a transmitter 110 in accordance withan embodiment of the present invention.

FIG. 6 depicts a flow chart diagram of determining the sensing value ofthe tip of transmitter or active stylus performed by a processingapparatus in accordance with an embodiment of the present invention.

FIG. 7A illustrates a block diagram of a transmitter 110 in accordancewith an embodiment of the present invention.

FIG. 7B illustrates a block diagram of a transmitter 110 in accordancewith an embodiment of the present invention.

FIG. 7C illustrates a block diagram of a transmitter 110 in accordancewith an embodiment of the present invention.

FIG. 7D illustrates a block diagram of a transmitter 110 in accordancewith an embodiment of the present invention.

FIG. 8 shows a flow chart of determining a sensing value of the tipsection of the transmitter in accordance with an embodiment of thepresent invention.

FIG. 9A shows a timing sequence of signal modulation in accordance withan embodiment of the present invention.

FIG. 9B shows a timing sequence of signal modulation in accordance withan embodiment of the present invention.

FIG. 9C shows a timing sequence of signal modulation in accordance withan embodiment of the present invention.

FIG. 9D shows a timing sequence of signal modulation in accordance withan embodiment of the present invention.

FIG. 9E shows a timing sequence of signal modulation in accordance withan embodiment of the present invention.

FIG. 9F shows a timing sequence of signal modulation in accordance withan embodiment of the present invention.

FIG. 10 shows noise propagation path in accordance with an embodiment ofthe present invention.

FIG. 11 depicts a structure diagram of a first capacitor 221 inaccordance with an embodiment of the present invention.

FIG. 12 shows a diagram of reduced embodiment shown in FIG. 11.

FIG. 13 is a variation of the embodiment shown in FIG. 12.

FIG. 14 is a variation of the embodiment shown in FIG. 13.

FIG. 15 is a variation of the embodiment shown in FIG. 14.

FIG. 16A shows a structure in accordance with an embodiment of thepresent invention.

FIG. 16B is a variation of the embodiment shown in FIG. 16A.

FIGS. 17A and 17B show structural diagrams of the first capacitor andthe second capacitor in accordance with an embodiment of the presentinvention.

FIG. 18 is a variation of the embodiment shown in FIG. 11.

FIG. 19A depicts a profiling diagram of the FSC structure used in thetransmitter 110 in accordance with an embodiment of the presentinvention.

FIG. 19B shows an assembled profiling diagram of the structure shown inFIG. 19A.

FIG. 19C shows another assembled profiling diagram of the structureshown in FIG. 19A.

FIG. 19D depicts a profiling diagram of the FSC structure used in thetransmitter 110 in accordance with an embodiment of the presentinvention.

FIG. 19E depicts a profiling diagram of the FSC structure used in thetransmitter 110 in accordance with an embodiment of the presentinvention.

FIG. 20 shows a profiling diagram of contact surface of the compressibleconductor 1974 facing the dielectric film 1973.

FIG. 21 illustrates a pressure sensor according to an embodiment of thepresent invention.

FIG. 22 illustrates a pressure sensor according to an embodiment of thepresent invention.

FIGS. 23A and 23B depict profiling diagrams of a switch structure inaccordance with an embodiment of the present invention.

FIGS. 24A and 24B depict profiling diagrams of a switch structure inaccordance with an embodiment of the present invention.

FIG. 25 shows a diagram for calculating the tip position.

FIG. 26 depicts a flow chart diagram for calculating the inclinationangle in accordance with the present invention.

FIG. 27 shows embodiments of how display interface reflects strobeaccording to the inclination angle and/or pressure of the tip section.

FIG. 28 depicts other embodiments of how display interface reflectsstrobe according to the inclination angle and/or pressure of the tip.

FIG. 29 illustrates a block diagram of a system for detecting beaconsignal in accordance with an embodiment of the present invention.

FIG. 30 depicts some waveforms of a spread spectrum technique.

FIG. 31 shows a variant of the embodiment as shown in FIG. 1.

FIG. 32 shows a flowchart of despreading method according to anembodiment of the present invention.

FIG. 33 depicts a diagram of an embodiment of an active stylus inaccordance with the present invention.

FIG. 34 shows a block diagram of a touch sensitive processing apparatus130 according to an embodiment of the present invention.

FIG. 35 illustrates a flowchart diagram practiced by the controller asshown in FIG. 33 in accordance to an embodiment of the presentinvention.

FIG. 36A illustrates a flowchart diagram practiced by the embeddedprocessor in accordance to an embodiment of the present invention.

FIG. 36B illustrates another flowchart diagram practiced by the embeddedprocessor in accordance to an embodiment of the present invention.

FIG. 37A illustrates a flowchart diagram practiced by the controller asshown in FIG. 33 in accordance to an embodiment of the presentinvention.

FIG. 37B illustrates another flowchart diagram practiced by thecontroller as shown in FIG. 33 in accordance to an embodiment of thepresent invention.

FIG. 38A illustrates a flowchart diagram practiced by the embeddedprocessor in accordance to an embodiment of the present invention.

FIG. 38B illustrates a flowchart diagram practiced by the embeddedprocessor in accordance to an embodiment of the present invention.

FIG. 39A illustrates a schematic diagram of a touch system in accordancewith an embodiment of the present invention.

FIG. 39B illustrates a schematic diagram of a variant of the touchsystem in accordance with an embodiment of the present invention.

FIG. 39C illustrates a schematic diagram of a variant of the touchsystem in accordance with an embodiment of the present invention.

FIG. 40 depicts a schematic diagram of a touch sensitive processingapparatus in accordance with an embodiment of the invention.

FIG. 41A illustrates a flowchart diagram of an operating methodapplicable to a corded stylus of an embodiment according to theinvention.

FIG. 41B illustrates a flowchart diagram of an operating methodapplicable to a corded stylus of an embodiment according to theinvention.

FIG. 41C illustrates a flowchart diagram of an operating methodapplicable to a corded stylus of an embodiment according to theinvention

FIG. 42 depicts a flowchart diagram applicable to a touch sensitiveprocessing apparatus according to an embodiment of the presentinvention.

FIG. 43 depicts a flowchart diagram applicable to a touch sensitiveprocessing apparatus according to an embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Some embodiments of the present invention are described in detailsbelow. However, in addition to the descriptions given below, the presentinvention can be applicable to other embodiments, and the scope of thepresent invention is not limited by such, rather by the scope of theclaims. Moreover, for better understanding and clarity of thedescription, some components in the drawings may not necessary be drawnto scale, in which some may be exaggerated relative to others, andirrelevant parts are omitted.

Please refer to FIG. 1, which illustrates a block diagram of a touchsensitive system 100 in accordance with an embodiment of the presentinvention. The touch sensitive system 100 comprises at least onetransmitter 110, a touch panel 120, a touch sensitive processingapparatus 130, and a host 140. The transmitter 110 may be an activestylus which emits electric signal in one embodiment of the presentinvention. However, the implementations of the transmitter 110 are notrestricted to that. The touch sensitive system 100 may comprises aplurality of transmitters 110. The touch panel 120 is formed on asubstrate. The touch panel 120 may be a touch sensitive screen. Thepresent application does not limit implementations of the touch panel120.

In one embodiment, the touch sensitive area of the touch panel 120includes a plurality of first electrodes 121 and a plurality of secondelectrodes 122. Multiple capacitive coupling sensing points are locatedwhere the intersections of these two kinds of electrodes. The first andsecond electrodes 121 and 122 are connected to the touch sensitiveprocessing apparatus 130, respectively. In a mutual capacitancedetecting mode, the first electrodes 121 may be called as drivingelectrodes, the second electrodes 122 may be called as sensingelectrodes. The touch sensitive processing apparatus 130 providesdriving voltage (voltage of driving signal) to those first electrodes121 and measures signal variation occurs to the second electrodes 122 todetecting foreign conductive object approximating or touching the touchpanel 120. Ordinary people skilled in the art could understand the touchsensitive processing apparatus 130 could use self-capacitance mode ormutual-capacitance mode to detecting approximating or touching event andobject. No description is elaborated further. In addition toself-capacitance mode or mutual-capacitance mode, the touch sensitiveprocessing apparatus 130 could further detect the electric signalemitted from the transmitter 110 to calculate a position of thetransmitter 110 in relative to the touch panel 120. In one embodiment,signal variations occurs to the first electrodes 121 and the secondelectrodes 122 are measured, respectively, to detect the electric signaland the position of the transmitter 110 in relative to the touch panel120. Since frequency of the electric signal emitted from the transmitter110 is not identical or harmonic to frequency of driving signals inself-capacitance mode or mutual-capacitance mode, the touch sensitiveprocessing apparatus 130 could distinguish the electric signals from thetransmitter 110 and the driving signals during self-capacitance mode ormutual-capacitance mode. In another embodiment, the touch panel 120 maybe surface capacitance touch sensitive panel which has four electrodesattaching to four corners or four sides. The touch sensitive processingapparatus 130 detects the position of the transmitter 110 in relative tothe touch panel 110 by measuring signal variations of these fourelectrodes.

A host 140 is also shown in FIG. 1. It could be a central processingunit, a master processor in an embedded system, or any other form ofcomputer. In one embodiment, the touch sensitive system 110 could be atablet computer. The host 140 could be a CPU which runs an operatingsystem of the tablet computer. For example, the tablet computer relieson Android operating system and the host 140 is an ARM processor whichruns Android operating system. The present application does not limitthe format of information transmitted between the host 140 and the touchsensitive processing apparatus 130. It only requires that theinformation is related to approximating or touching event occurs to thetouch panel 120.

Since electric signals are emitted, the transmitter 110 or active stylusneeds electric power to supply the energy of electric signals. In oneembodiment, power source of the transmitter 110 may be battery or arechargeable battery. Alternatively, power source of the transmitter 110may be capacitor, especially a ultra-capacitor or a super-capacitor,such as one of EDLC (Electrical Double Layered Capacitor),pseudo-capacitor, and hybrid capacitor. The charging time ofultra-capacitor is counted in seconds and the discharging time iscounted in hours. In other words, active stylus endures long requiringshort charging time.

In one embodiment, the touch panel 120 periodically emits a beaconsignal. When the tip of the transmitter 110 or active stylus contactsthe touch panel 120, the transmitter 110 could detect the beacon signalvia the tip. In response to the detection, the transmitter 110 begins toemit the electric signal for a while to the touch panel 120.Consequently, the transmitter 110 may stop emitting the electric signalif no beacon signal is detected. Thus the operating time of thetransmitter could be extended accordingly.

The beacon signal could be emitted via the first electrodes 121 and/orthe second electrodes 122. In one embodiment, in case driving signalsare transmitted from the first electrodes for mutual capacitancedetection, frequency of the driving signals is not identical or harmonicto frequency of the beacon signal. Therefore it is possible to transmitthe driving signals and the beacon signals simultaneously. In otherwords, mutual-capacitance detection and the electric signal detectioncould be performed simultaneously. Alternatively, it takes turn totransmit the driving signals and the beacon signals. Thusmutual-capacitance detection and the electric signal detection are donein time-sharing fashion. In such case, frequency of the driving signalsmay or may not be identical to frequency of the beacon signals.

In one embodiment, in order to make the transmitter 110 detecting thebeacon signals further away above the touch panel 120, the touchsensitive processing apparatus 130 commands all of the first and thesecond electrodes 121 and 122 of the touch panel 120 emitting thedriving signals simultaneously, such that the total signal strengthemitted from the touch panel 120 could be maximized.

Please refer to FIG. 2, which depicts a block diagram of a transmitter110 in accordance with an embodiment of the present invention. Thetransmitter 110 comprises a first signal source 211, a second signalsource 212, a first component 221 with a first impedance Z1, a secondcomponent 222 with a second impedance Z2, and a tip section 230. A firstsignal emitted from the first signal source 211 transmits to the touchpanel 120 via the first component 221 and the tip section 230.Similarly, a second signal emitted from the second signal source 212transmits to the touch panel 120 via the second component 222 and thetip section 230.

In one embodiment, the first signal includes a signal with a firstfrequency f1, the second signal includes a signal with a secondfrequency f2. The first signal with frequency f1 and the second signalwith frequency f2 may be square-wave signals, sinuous signals, or PWM(pulse width modulation) signals. In one embodiment, the first frequencyf1 is not identical or harmonic to frequency of the beacon signal andfrequency of the driving signal. The second frequency f2 does not equalto the first frequency f1. Furthermore, the second frequency f2 is notidentical or harmonic to frequency of the beacon signal and frequency ofthe driving signal.

These signals with two frequencies get mixed and fed into the tipsection 230 via the first component 221 with the first impedance Z1 andthe second component 222 with the second impedance Z2, respectively. Thefirst and second components 221 and 222 could be any combination ofresistor, inductor, and capacitor (e.g. solid state capacitor). In theembodiment as shown in FIG. 2, the second impedance Z2 is fixed orconstant; the first impedance Z1 is variable or adjustable correspondingto a sensing variation of a sensor.

In another embodiment, the first and second impedances Z1 and Z2 bothare variable or adjustable. A ratio of these two impedances iscorresponding to a sensing variation of a sensor. In one embodiment, thesensor may be a contractible and flexible tip. The first impedance Z1changes corresponding to the stroke or the pressure level of theflexible tip. In some examples, the first impedance Z1 is linearlyproportional to the variation of the sensing value of the sensor. Inalternative examples, the first impedance Z1 is non-linearlyproportional to the variation of the sensing value of the sensor.

The first and second components 221 and 222 may not be the same kind ofelectric component. For example, the first component 221 is a resistorand the second component 222 is a capacitor, and vice versa. In anotherexample, the first component 221 is a resistor and the second component222 is an inductor, and vice versa. Alternatively, the first component221 is an inductor and the second component 222 is a capacitor, and viceversa. At least one of the first impedance Z1 and the second impedanceZ2 is variable or adjustable. For example, it may be resistor withvariable resistance, capacitor with variable capacitance, or inductorwith variable inductance. In case of one of the first impedance Z1 andthe second impedance Z2 is fixed or constant; the component may be oneof the following: resistor with fixed resistance, capacitor with fixedcapacitance, or inductor with fixed inductance.

In one embodiment, the first component 221 may be a FSR, force sensingresistor, with a variable and determinable resistance corresponding toan applied force, and the second component 222 may be a resistor withfixed resistance. In alternative embodiment, the first component may bea resistor with variable resistance. Hence, while other conditions arethe same, a ratio of a first strength M1 of signal component with thefirst frequency f1 and a second strength M2 of signal component with thesecond frequency f2 in the electric signals emitted from the tip section230 is proportional to an inverse ratio of the first and the secondimpedances Z1 and Z2. In other words, M1/M2=k (Z2/Z1).

When the transmitter 110 hovers above the touch panel 120, since the tipsection 230 is not pressed or moved, the ratio between strength M1 ofsignal component with the first frequency f1 and strength M2 of signalcomponent with the second frequency f2 is a constant or a predeterminedvalue. Or alternatively, a ratio of (M1−M2)/(M1+M2) or another ratio of(M2−M1)/(M1+M2) is also a constant or a predetermined value. Inaddition, the pressure level may be represented as M1/(M1+M2) orM2/(M1+M2). Except for those four ratios mentioned above, ordinarypeople skilled in the art could use any other ratio involving strengthsM1 and M2. In other words, when the detected ratio is the constant orthe predetermined value, it is concluded that the sensor did not senseany variation. In one embodiment, it means that the transmitter 110 doesnot contact the touch panel 120.

When the transmitter 110 contacts the touch panel 120, the tip section230 is pressed to move. The first impedance Z1 of the first component221 changes according to the movement or the pressure of the tip section230 such that the ratio of M1 and M2 is varied accordingly from theconstant or the predetermined value. The touch panel 120 could generatecorresponding sensing (pressure) value according to the ratio. Thefore-mentioned constant or predetermined value may not be a number but arange with a tolerable error.

It is noticeable that the relation between the ratio and the sensingvalue may not be linear. Furthermore, the sensing value may not belinearly proportional to the movement or the pressure of the sensor. Thesensing value is just a value sensed by the touch panel 120. The presentapplication does not limit the correspondence of the sensing value. Forexample, the touch panel 120 could generate the sensing value accordingto the ratio by looking into a look-up table or by calculations.

Please refer to FIG. 3, which shows a block diagram of a transmitter 110in accordance with an embodiment of the present invention. Similar tothe embodiment shown in FIG. 2, the transmitter 110 comprises the firstsignal source 211, the second signal source 212, a first capacitor 321with a first capacitance C1, a second capacitor 322 with a secondcapacitance C2, and the tip section 230.

The two signal sources 211 and 212 may be a first PWM signal source PWM1and a second PWM signal source PWM2, respectively. These two signalsources 211 and 212 may emit signals with the same frequency or not. Thetransmitter 110 comprises the second capacitor 322 with fixed secondcapacitance C2 and the first capacitor 321 with a variable firstcapacitance C1, which are connected to the signal sources PWM2 212 andPWM1 211, respectively. Since the first capacitance C1 changes accordingto the pressure level of the tip section 230, the embodiment shown inFIG. 3 may comprises a capacitive force sensor or a FSC, force sensingcapacitor. In one embodiment, the capacitive force sensor may beimplemented by PCB (printed circuit board) or any other material. Thestructure of the FSC would be described in paragraphs below.

The strength ratio of these two signal sources is inversely proportionalto resistances of these two capacitors 321 and 322. When the tip section230 of the stylus does not touch, or the force sensor does not sense anyforce, resistance of the first capacitor 321 remains the same. Theresistance ratio of these two capacitors 321 and 322 keeps unchanged.When the transmitter 110 hovers above the touch panel 120 and theemitted electric signals are detected, the strength ratio of these twosignal sources is constant or fixed.

However, if the tip section 230 of the transmitter 110 is touched or theforce sensor does sense force, the resistance of the first capacitor 321changes accordingly such that the resistance ratio of these twocapacitors 321 and 322 also changes accordingly. When the transmitter110 contacts the touch panel 120 and the emitted electric signals aredetected, the strength ratio of these two signal sources is variedaccording to the force sensed by the force sensor.

Please refer to FIG. 4A, which depicts a block diagram of a transmitter110 in accordance with an embodiment of the present invention. Similarto the embodiment as shown in FIG. 3, the transmitter 110 comprises thefirst signal source 211, the second signal source 212, the firstcapacitor 321 with the first capacitance C1, the second capacitor 322with the second capacitance C2, and the tip section 230. The transmitter110 may comprise multiple sensors to detect multiple states. In oneembodiment, the tip section 230 comprises a force sensor for detectingthe pressure level of the tip and reflecting the pressure level to theemitted electric signal. In another embodiment, the transmitter 110 maycomprise multiple buttons, such as eraser button and barrel button.Alternatively, the transmitter 110 may include a switch to reflectwhether the tip is touched by the touch panel or anything else. Personshaving ordinary skill in the art could understand that the transmitter110 may include more buttons and other forms of sensors but not limitedto those mentioned.

In the embodiment shown in FIG. 4A, the first capacitor 321 connects toan eraser capacitor 441 and a barrel capacitor 442 in parallel, whichare connected in series to the eraser button and the barrel button, orswitch SWE and switch SWB, respectively. When the corresponding buttonis pressed or the corresponding switch is shorted, the capacitor 441 or442 is connected to the first capacitor 321 in parallel, such that itchanges the capacitance of the PWM1 signal path and the resistance ratiobetween the PWM1 signal path and the PWM2 signal path is changedaccordingly. Thus the strength ratio of these two signal sources isvaried in consequence.

Since the capacitance C1 and resistance of the first capacitor 321 isvariable, in case it is connected in parallel with the eraser capacitor441 and the barrel capacitor 442, the resistance ratio of the connectedcircuit and the second capacitor 322 resides in a range. In theembodiment as shown in FIG. 4A, assuming the signal strength ratio ofPWM1 versus PWM2 falls into a first range in response to the variablerange of the first capacitor 321. In case the first capacitor 321 isconnected with the barrel capacitor 442 in parallel, i.e., the barrelbutton is pressed, the signal strength ratio of PWM1 versus PWM2 fallsinto a second range. In case the first capacitor 321 is connected withthe eraser capacitor 441 in parallel, i.e., the eraser button ispressed, the signal strength ratio of PWM1 versus PWM2 falls into athird range. Further, in case the first capacitor 321 is connected withthe barrel capacitor 442 and the eraser capacitor 441 in parallel, i.e.,the barrel button and the eraser button are pressed, the signal strengthratio of PWM1 versus PWM2 falls into a fourth range. In theimplementation, the capacitance and resistance of the barrel capacitor442 and the eraser capacitor 441 could be adjusted such that the first,second, third, and four ranges are not overlapped. Because the rangesare not overlapped, it is able to determine which button is pressedaccording to which range the signal strength ratio falls into. Inconsequence, the pressure level of the force sensor could be concludedaccording to the signal strength ratio.

Please refer to FIG. 4B, which depicts a block diagram of a transmitter110 in accordance with an embodiment of the present invention. Comparingwith the embodiment shown in FIG. 4A, the second capacitor 322 isconfigured to connected with the eraser capacitor 441 and the barrelcapacitor 442, which are connected in series to the eraser button andthe barrel button, or switch SWE and switch SWB, respectively. When thecorresponding button is pressed or the corresponding switch is shorted,the capacitor 441 or 442 is connected to the second capacitor 322 inparallel, the resistance ratio between the PWM1 signal path and the PWM2signal path is changed accordingly. Thus the strength ratio of these twosignal sources is varied in consequence.

Since the capacitance Cl and resistance of the first capacitor 321 isvariable, in case the second capacitor 322 is connected in parallel withthe eraser capacitor 441 and the barrel capacitor 442, the resistanceratio of the connected circuit and the first capacitor 321 resides in arange. In the embodiment shown in FIG. 4B, assuming the signal strengthratio of PWM1 versus PWM2 falls into a first range in response to thevariable range of the first capacitor 321. In case the second capacitor322 is connected with the barrel capacitor 442 in parallel, i.e., thebarrel button is pressed, the signal strength ratio of PWM1 versus PWM2falls into a fifth range. In case the second capacitor 322 is connectedwith the eraser capacitor 441 in parallel, i.e., the eraser button ispressed, the signal strength ratio of PWM1 versus PWM2 falls into asixth range. Further, in case the second capacitor 322 is connected withthe barrel capacitor 442 and the eraser capacitor 441 in parallel, i.e.,the barrel button and the eraser button are pressed, the signal strengthratio of PWM1 versus PWM2 falls into a seventh range.

Utilizing the same spirit embodied in FIG. 4A, the capacitance andresistance of the barrel capacitor 442 and the eraser capacitor 441could be adjusted such that the first, fifth, sixth, and seventh rangesare not overlapped. Because the ranges are not overlapped, it is able todetermine which button is pressed according to which range the signalstrength falls into. In consequence, the pressure level of the forcesensor could be concluded according to the signal strength ratio.

Please refer to FIG. 5, which depicts a block diagram of a transmitter110 in accordance with an embodiment of the present invention. Theembodiment as shown in FIG. 5 may be variation of embodiments shown inFIG. 2, 3, 4A, and 4B. Reversely, the variation of the embodiment shownin FIG. 5 apply to the embodiments shown in FIG. 2, 3, 4A, and 4B.

Comparing with the embodiment shown in FIG. 2, the embodiment shown inFIG. 5 further comprises a ring electrode 550 and a ring wire 551. Thering wire 551 as shown in FIG. 5 connects to a third signal source 513via a ring capacitor 523 with a fixed capacitance Cr. The tip section230 is surrounded by the ring electrode 550 which is coupled to the ringwire 551 and the printed circuit board in the aft. Although it is called“ring” electrode 550 in the present application, the ring electrode 550may comprise multiple electrodes in some embodiments. The presentinvention does not limit the number of the ring electrode 550. Forconvenience, they are collectively called ring electrode 550. The ringelectrode 550 is electrically insulated to the tip section. They are notelectrically coupled.

Six switches Swl through Sw6 are shown in FIG. 5. The tip section 230radiates signals from the first signal source 211 if the switch Sw1 isshorted and switch Sw2 is opened. Otherwise, it could be done if theswitch Sw1 is opened or in case the switches Sw1 and Sw2 are shorted.Similarly, the tip section 230 radiates signals from the second signalsource 212 if the switch Sw3 is shorted and switch Sw4 is opened.Otherwise, it could be done if the switch Sw3 is opened or in case theswitches Sw3 and Sw4 are shorted. The ring electrode 550 radiatessignals from the third signal source 513 if the switch Sw5 is shortedand switch Sw6 is opened. Otherwise, it could be done if the switch Sw5is opened or in case the switches Sw5 and Sw6 are shorted.

The first signal source 211 and the second signal source 212 may emitsignals with different frequencies or signals with different frequencygroups. Analogously, the third signal source 513 may emit signals withfrequency or frequency group different to those from the first signalsource 211 and the second signal source 212. Similarly, the first signalsource 211 and the second signal source 212 may transmit PWM signals.The frequency of signals transmitted from these two signal sources 211and 212 may be identical or not. Comparably, the third signal source 513may transmit PWM signals. The frequency of signals transmitted fromthese three signal sources 211, 212 and 513 may be identical or not.

Please refer to FIG. 6, which depicts a flow chart diagram ofdetermining the sensing value of the tip of transmitter or active stylusperformed by a processing apparatus in accordance with an embodiment ofthe present invention. The method could be executed by the touchsensitive processing apparatus 130 as shown in FIG. 1. The touchsensitive processing apparatus 130 connects multiple first electrodes121 and second electrodes 122 of the touch panel 120 for detecting theelectric signals emitted by the tip section 230 of the transmitter 110.The touch sensitive processing apparatus 130 is able to determine aposition the transmitter 100 in relative to the touch panel 120according to signal strengths received by individual first electrode 121and second electrode 122. In addition, method shown in FIG. 6 isconfigured to determine the force sensing value of the transmitter 110.In one instance, the force sensing value is the pressure level of thetip section 230.

The embodiment shown in FIG. 6 may be corresponding to the embodimentsshown in FIG. 2 through FIG. 5. The first two steps 610 and 620 arecalculating signal strength M1 and M2 of the first signal source 211 andthe second signal source 212, respectively. These two steps 610 and 620could be done simultaneously or in any order. In case the signal fromthe first signal source 211 with first frequency f1 and the signal fromthe second signal source 212 with second frequency f2, the signalstrength M1 is the strength of signal with f1 and the signal strength M2is the strength of signal with f2. In case the signal from the firstsignal source 211 with first frequency group F1 and the signal from thesecond signal source 212 with second frequency group F2, the signalstrength M1 is sum of strength of signals with each frequency of groupF1 and the signal strength M2 is sum of strength of signals with eachfrequency in group F2. As mentioned above, the frequency in thisembodiment could be PWM frequency.

Then in step 630, calculating a ratio according to M1 and M2. Fiveexamples of the ratio are already enumerated above, such as M1/M2,(M1−M2)/(M1+M2), (M2−M1)/(M1+M2), M1/(M1+M2), and M2/(M1+M2). Personshaving ordinary skill in the art could use any other ratio involving M1and M2 in addition to those examples. Next, step 640 is performed fordetermining whether the ratio is a predetermined value or falls into apredetermined range. If the result is true, the flow goes to step 650.It is determined that the transmitter 110 is hovering above the touchpanel 120. Otherwise, the flow executes step 660 for calculating asensing value of the tip section 230 according to the ratio. The sensingvalue may or may not be relevant to the pressure level or movingdistance of the tip section 230. The calculations of the sensing valuecould be done by looking into a lookup table, linear interpolation,and/or quadratic curve interpolation. It depends on the relation betweenthe ratio and the sensing value.

When the method shown in FIG. 6 applies to the embodiments shown in FIG.4A and 4B, additional steps could be performed in step 660. For example,when it applies to the embodiment shown in FIG. 4A, the flow may furtherdetermine which one of the first, second, third, and fourth ranges theratio calculated in step 630 falls into. Hence, it is able to determinewhether the barrel button and/or the eraser button are pressed or not inaddition to the sensing value of the tip section 230. Analogously, whenit applies to the embodiment shown in FIG. 4B, the flow may furtherdetermine which one of the first, fifth, sixth, and seventh ranges theratio calculated in step 630 falls into. Hence, it is able to determinewhether the barrel button and/or the eraser button are pressed or not inaddition to the sensing value of the tip section 230.

In one embodiment of the present application, the controller or circuitinside the transmitter 110 does not need to determine the pressure levelof the tip section 230. It simply requires that one or both the firstimpedance Z1 of the first component 221 and the second impedance Z2 ofthe second component 222 change according to the pressure level of thetip section 230 such that one of the signal strength of first frequencyf1 or first frequency group F1 and the signal strength of secondfrequency f2 or second frequency group F2 change in consequence.Therefore the pressure level of the tip section 230 could be calculatedaccording to a ratio between the strength M1 of signals with firstfrequency f1 or first frequency group F1 and the strength M2 of signalswith second frequency f2 or second frequency F2 is demodulated from theelectric signals received by the touch panel 120.

Please refer to FIG. 7A, which illustrates a block diagram of atransmitter 110 in accordance with an embodiment of the presentinvention. Comparing with embodiments shown in FIG. 2 through FIG. 5,the transmitter 110 shown in FIG. 7A also comprises a first component221 with a first impedance Z1, a second component 222 with a secondimpedance Z2, and a tip section 230. The first component 221 and thesecond component 222 may be any combination of resistor, inductor, andcapacitor. In the embodiment as shown in FIG. 7A, the second impedanceZ2 may be fixed and the first impedance Z1 is variable or adjustablecorresponding to a variation of a sensor, such as pressure level of thetip section 230. The first component 221 and the second component 222 asshown in FIG. 7A could adopt those components with same numerals shownin FIG. 2 through FIG. 5. No duplicated description is elaborated here.

Comparing with the previous embodiments, the difference resides in theembodiment shown in FIG. 7A is including a single signal source 714which is configured to transmit electric signals to the first component221 and the second component 222 and a controller 760 which isconfigured to measure a first current value I1 and a second currentvalue I2 outputted from the first component 221 and the second component222, respectively. The controller 760 is further configured tocalculated a ratio which may be one of the followings: I1/(I1+I2),I2/(I1+I2), I1/I2, (I1−I2)/(I1+I2), (I2−I1)/(I1+I2) and etc. Personshaving ordinary skill in the art can calculated any other ratioinvolving the current values I1 and I2.

The calculated ratio could be used to conclude the pressure level of thetip section 230. The controller 760 can transmit information derivedfrom the first current value I1 and the second current value I2 via atransmitter wireless communication unit 770. The host 140 may receivethe information via a host wireless communication unit 780 to get thepressure level of the tip section 230.

Please refer to FIG. 7B, which illustrates a block diagram of atransmitter 110 in accordance with an embodiment of the presentinvention. The difference to the embodiment shown in FIG. 7A residesthat the controller 760 may transmit information derived from the firstcurrent value I1 and the second current value I2 via a transmitter wiredcommunication unit 771. The host 140 may receive the information via ahost wired communication unit 781 to get the pressure level of the tipsection 230.

Please refer to FIG. 7C, which illustrates a block diagram of atransmitter 110 in accordance with an embodiment of the presentinvention. The difference to the embodiment shown in FIG. 7B residesthat the transmitter 110 no longer has the single signal source 714.Instead, the transmitter 110 uses the electric signal from thetransmitter wired communication unit 771 as the signal source. Since thetransmitter wired communication unit 771 is connected to the host wiredcommunication unit 781, the electric signal is supplied by the power ofthe host 140.

Please refer to FIG. 7D, which illustrates a block diagram of atransmitter 110 in accordance with an embodiment of the presentinvention. The difference to the embodiment shown in FIG. 7A residesthat the transmitter 110 no longer has the single signal source 714.Instead, the transmitter 110 uses received signal from the firstelectrodes 121 and/or the second electrodes 122 of the touch panel 120when the tip section 230 approximating or touching the touch panel 120.

It is worthy mentioned that the embodiments shown in FIG. 7A through 7Dcould use the variation shown in FIG. 3. The first component 221 may bethe fore-mentioned first capacitor 321. The second component 222 may bethe fore-mentioned second capacitor 322. Similarly, the embodimentsshown in FIG. 7A through 7D could use the variations shown in FIG. 4Aand 4B. The first component 221 may be connected with componentcorresponding to other switch in parallel, or the second component 222may be connected with components corresponding to other switch inparallel, such that the controller 760 could conclude the state of theswitch according to which range where the calculated ratio falls into.

Please refer to FIG. 8, which shows a flow chart of determining asensing value of the tip section of the transmitter performed by a touchsensitive processing apparatus in accordance with an embodiment of thepresent invention. The embodiment shown in FIG. 8 is quite similar tothe embodiment shown in FIG. 6, which is configured to calculate thesensing value according to a ratio between a signal strength M1 of afirst frequency (group) and a signal strength M2 of a second frequency(group). The embodiment shown in FIG. 8 is configured to apply toimplementation with a single signal source, which is configured tocalculate the ratio between a first current value I1 through the firstcomponent 221 and a second current value I2 through the second component222.

The method may be executed by the controller 760 of the embodimentsshown in FIG. 7A through 7D. The first two steps 810 and 820 areconfigured for calculating a first current value I1 through the firstcomponent 221 and a second current value I2 through the second component222, respectively. These two steps 810 and 820 may be performedsimultaneously, or in any order. Next, in step 830, calculating a ratioof I1 and I2. Several examples of the ratio are already enumeratedabove, such as I1/(I1+I2), I2/(I1+I2), I1/I2, I2/I1, (I1−I2)/(I1+I2),(I2−I1)/(I1+I2), and etc. Next, in step 840, determining whether theratio is a predetermined value or falls into a predetermined range. Ifthe result is true, the flow goes to step 850, it is determined that thetransmitter is hovering above the touch panel 120. Otherwise, the flowgoes to step 860, calculating a sensing value of the tip sectionaccording to the ratio. The sensing value may or may not be relevant tothe pressure level or moving distance of the tip section 230. Thecalculations of the sensing value could be done by looking into a lookuptable, linear interpolation, and/or quadratic curve interpolation. Itdepends on the relation between the ratio and the sensing value.

When the method shown in FIG. 8 applies to the embodiments shown in FIG.4A and 4B, additional steps could be performed in step 860. For example,when it applies to the embodiment shown in FIG. 4A, the flow may furtherdetermine which one of the first, second, third, and fourth ranges theratio calculated in step 830 falls into. Hence, it is able to determinewhether the barrel button and/or the eraser button are pressed or not inaddition to the sensing value of the tip section 230. Analogously, whenit applies to the embodiment shown in FIG. 4B, the flow may furtherdetermine which one of the first, fifth, sixth, and seventh ranges theratio calculated in step 830 falls into. Hence, it is able to determinewhether the barrel button and/or the eraser button are pressed or not inaddition to the sensing value of the tip section 230.

Please refer to FIG. 9A, which shows a timing sequence of signalmodulation in accordance with an embodiment of the present invention.The embodiment shown in FIG. 9A may apply to the transmitter 110 asshown in FIG. 2 through FIG. 5. The horizontal axis of FIG. 9A is a timeaxis by order from left to right. As shown in FIG. 9A, an optional noisedetection period is included prior to a beacon signal is emitted by thetouch panel 120. The noise detected during the period may come fromtouch panel, the electronics, and/or background environment. The touchpanel 120 and the touch sensitive processing apparatus 130 may detectone or more frequencies of noise signals. Noise detection would bedescribed later.

In one embodiment, the touch panel 120 transmits beacon signals. Thetransmitter 110 comprises a demodulator for detecting the beacon signal.Please refer to FIG. 29, which illustrates a block diagram of a systemfor detecting beacon signal in accordance with an embodiment of thepresent invention. The system 2900 comprises a receiving electrode 2910,a detecting module 2920, and a demodulator 2930. In one embodiment, thereceiving electrode 2910 may be the ring electrode 550, the tip section230, or any other electrodes. The receiving electrode 2910 forwards thereceived signal to the detecting module 2920.

The detecting module comprises an analogous front end 2911 and acomparator 2912. Persons having ordinary skill in the art couldunderstand what analogous front end 2911 does which is not elaboratedhere. In this embodiment, the analogous 2911 outputs a voltage signalrepresenting the signal strength. The comparator 2912 is configured tocompare a reference voltage Vref and a voltage signal representing thesignal strength. If the voltage signal is higher than the referencevoltage, it means that the received signal is strong enough. Thus, thecomparator 2912 outputs an activation signal or an enable signal to thedemodulator 2930 which is configured to demodulate the received signalto determine whether the received signal contains the frequency of thebeacon signal. If the voltage signal is lower than the referencevoltage, the comparator 2912 may output a disable signal to thedemodulator 2930. Therefore the demodulator 2930 stops demodulating thereceived signal.

When the transmitter 110 did not receive the beacon signal for a while,it could be switched to a sleep mode for shutting the demodulator 2930down to reduce power consumption. However, since the power consumptionof the detecting module 2920 is not significant, it could continuedetecting whether the signal strength of the received signal is over apredetermined value in the sleep mode. Once it is more than thepredetermined value, the transmitter 110 may switch from the sleep modeto an energy saving mode which consume more power for activating thedemodulator 2930. In the same time, the rest of the transmitter 110 maystill rest in the power down state. If the demodulator 2930 determinesthat the received signal does not contain the beacon signal, thedemodulator 2930 may be shut down after some time and the transmitter110 switches from the energy saving mode back to the sleep mode whichconsume less power. Instead, if the demodulator 2930 determines that thereceived signal does contain the beacon signal, the demodulator 2930 canwake up the rest parts of the transmitter 110 such that the transmitterswitches from the energy saving mode to normal working mode.

Now, back to embodiment of FIG. 9A, after a delay period enduring L0length, the transmitter 110 emits electric signal during T0 and T1periods. There may exist a delay period enduring L1 length between theT0 and T1 periods. The length of T0 period may or may not equal to thelength of T1 period. The T0 and T1 periods are collectively called asignal frame. The touch sensitive processing apparatus 130 detects theelectric signals emitted from the transmitter 110 during T0 and T1periods. Next, after another optional delay time enduring L2 length, thetouch sensitive processing apparatus 130 may perform optional otherdetection, e.g., fore-mentioned capacitance detection mode for detectingpassive stylus or finger.

The present invention does not limit the lengths of delay times L0, L1,and L2, which may be zero or any other duration. The lengths of delaytimes L0, L1, and L2 may or may not be relevant. In one embodiment,among those periods shown in FIG. 9A, only the T0 and T1 periods of thesignal frame are mandatory, other periods are optional.

TABLE 1 Barrel Eraser button button State Signal Source Period pressedpressed Other state hovering 1^(st) signal source T0 F0 F1 F0 T1 F1 F2F2 2^(nd) signal source T0 F0 F1 F0 T1 F1 F2 F2

Please refer to Table 1, which shows a modulation table of electricsignals emitted by the transmitter 110 in accordance with an embodimentof the present invention. As shown in Table 1, the state of thetransmitter 110 is hovering, i.e., no pressure is measured by the forcesensor. Since the tip section 230 of the transmitter 110 does notcontact the touch panel 120, the first and second signal sources 211 and212 emit the same frequency group Fx simultaneously in the same periodin order to enhancing the signal strength in the embodiment shown inTable 1. For example, in case the barrel button is pressed, these twosignal sources both emits frequency group F0 during the T0 period andfrequency F1 during the T1 period. If the touch sensitive processingapparatus 130 detects signals with frequency group F0 during the T0period and signals with frequency group F1 during the T1 period, it isdetermined that the barrel button of the hovering transmitter 110 ispressed.

The frequency group Fx comprises at least one frequency. Frequenciesclassified in the same frequency group are interchangeable. For example,frequency group F0 comprises f0 and f3 frequencies; frequency group F1comprises f1 and f4 frequencies; and frequency group F2 comprises f2 andf5 frequencies. No matter which one of f0 and f3 frequencies isdetected, the touch sensitive processing apparatus 130 takes thatfrequency group F0 is received.

In another embodiment, it is not required to have both signal sources211 and 212 of the transmitter 110 emitting signals with the samefrequency group. Table 1 is just an example of the present embodiment.Besides, the transmitter 110 may comprises more buttons or sensors. Thepresent invention does not limit to two buttons.

TABLE 2 Barrel Eraser button button State Signal Source Period pressedpressed Other state Touching 2^(nd) signal source T0 F0 F1 F0 T1 GND GNDGND 1^(st) signal source T0 GND GND GND T1 F1 F2 F2

Please refer to Table 2, which shows a modulation table of electricsignals emitted by the transmitter 110 in accordance with an embodimentof the present invention. As shown in Table 2, the state of the tipsection 230 of the transmitter 110 is touching, i.e., pressure ismeasured by the force sensor.

With regard to the embodiment shown in FIG. 4A, the following describeswhat happened if the barrel button is pressed. During the T0 period, thefirst signal source output is grounded and the second signal sourceemits signals with frequency group F0. During the T1 period, the secondsignal source output is grounded and the first signal source emitssignals with frequency group F1. Furthermore, since the impedance of thefirst capacitor 321 is changed in the touching state, the pressure levelof the tip section 230 could be calculated according to the signalstrengths with regard to frequency groups F0 and F1 during the T0 and T1periods, respectively. Besides, because the touch sensitive processingapparatus 130 detects frequency group F0 during the T0 period anddetects frequency group F1 during the T1 period, it is determined thatthe barrel button is pressed.

With regard to the embodiment shown in FIG. 4A, the following describeswhat happened if the barrel button is pressed. During the T0 period, thefirst signal source output is grounded and the second signal sourceemits signals with frequency group F0. The second capacitor 322 isconnected with the barrel capacitor 442 in parallel. Although theelectric signals emitted from the transmitter 110 during the T0 periodonly contains signals with frequency group F0 from the 2^(nd) signalsource, the signal strength is different from the one which the barrelbutton is not pressed. During the T1 period, the second signal sourceoutput is grounded and the first signal source emits signals withfrequency group F1. Furthermore, since the impedance of the firstcapacitor 321 is changed in the touching state, the pressure level ofthe tip section 230 could be calculated according to the signalstrengths with regard to frequency groups F0 and F1 during the T0 and T1periods, respectively. Besides, because the touch sensitive processingapparatus 130 detects frequency group F0 during the T0 period anddetects frequency group F1 during the T1 period, it is determined thatthe barrel button is pressed.

TABLE 3 Barrel Eraser button button State Signal Source Period pressedpressed Other state hovering 2^(nd) signal T0 F0 F1 F2 source T1 F0 F1F2 1^(st) signal T0 F0 F1 F2 source T1 F0 F1 F2

Please refer to Table 3, which shows a modulation table of electricsignals emitted by the transmitter 110 in accordance with an embodimentof the present invention. In this embodiment, according to the receivedfrequency group, it is able to know which button is pressed.

TABLE 4 Barrel Eraser button button State Signal Source Period pressedpressed Other state Touching 2^(nd) signal T0 F0 F1 F2 source T1 GND GNDGND 1^(st) signal T0 GND GND GND source T1 F0 F1 F2

Please refer to Table 3, which shows a modulation table of electricsignals emitted by the transmitter 110 in accordance with an embodimentof the present invention. In this embodiment, according to the receivedfrequency group, it is able to know which button is pressed. Thepressure level of the tip section could be calculated according to areceived signal strength ratio between the T0 and T1 periods.

Please refer to FIG. 9B, which shows a timing sequence of signalmodulation in accordance with an embodiment of the present invention.The embodiment is a variation of the embodiment shown in FIG. 9A. Thedifference resides between these two embodiments shown in FIG. 9A and 9B is that a noise detection taking place after the T1 period. Afterthat, other detection is performed.

Please refer to FIG. 9C, which shows a timing sequence of signalmodulation in accordance with an embodiment of the present invention.The modulation shown in FIG. 9C may apply to the transmitter 110 shownin FIG. 5. One additional function of the ring electrode 550 is toenhancing emitted signal strength of active stylus. Thus the detectionrange of the hovering active stylus could be increased consequently.

The modulation shows in FIG. 9C is when the transmitter 110 is hovering.In this state, the time period which the transmitter 110 emits signalscontains the R time period, merely. During this R period, both the ringelectrode 550 and the tip section 230 transmit electric signalstogether. In one embodiment, the electric signals may come from the samesignal source with the same frequency and modulations. For example, boththe ring electrode 550 and the tip section 230 transmit signals from thesignal source 513. In another instance, both the ring electrode 550 andthe tip section 230 may simultaneously transmit signals from the first,the second, and the third signal sources in turns, such that it utilizesthe maximum power of each signal sources. The touch sensitive processingapparatus 130 can conclude the position the transmitter 110 is hoveringabove the touch panel 120 by detecting the electric signals emitted fromthe ring electrode 550 during the R period. If the electric signals fromthe ring electrode 550 and the tip section 230 comes from the samesignal source or have the same frequency group, the signal strengthwould be maximized. In consequence, the detecting range of the hoveringtransmitter 110 by the touch panel 120 would be maximized.Alternatively, the transmitter 110 transmits electric signals via onlythe ring electrode 550 during the R period.

Please refer to FIG. 9D, which shows a timing sequence of signalmodulation in accordance with an embodiment of the present invention.The modulation shown in FIG. 9D may apply to the transmitter 110 shownin FIG. 5. In the embodiment shown in FIG. 9C, a delay time or blankperiod L1 is included after the R period. The touch panel 120 performsother detection after the period L1. Comparing with the embodiment shownin FIG. 9C, the period L1 in the embodiment shown in FIG. 9D isextended. Comparing with the embodiment shown in FIG. 9E, he period L1in the embodiment shown in FIG. 9D equals to the sum of L1, T0, L2, T1,and T3 periods. Thus, if no further electric signal could be detected bythe touch sensitive processing apparatus 130 shown in FIG. 9D, it isdetermined that the transmitter 110 is in the state of hovering.

Please refer to FIG. 9E, which shows a timing sequence of signalmodulation in accordance with an embodiment of the present invention.The modulation shown in FIG. 9E may apply to the transmitter 110 shownin FIG. 5. The embodiment shown in FIG. 9E is equivalent to add an Rperiod prior to the time frame of the embodiment shown in FIG. 9A. Inthis embodiment, no matter whether the tip section 230 is touched ornot, the transmitter 110 always transmits electric signal from the tipsection during the T0 and T1 periods such that some logic design forcontrolling could be omitted. However, comparing with the embodimentsshown in FIG. 9C and 9 D, the embodiment shown in FIG. 9E would wastepower consumed during the T0 and T1 periods. On the other hand, thetouch sensitive processing apparatus 130 no longer needs to performdetection during the R period as long as the electric signals from thetip section 230 could be detected during the T0 and T1 periods. It couldbe determined that whether the tip section 230 is pressed or not andfurther determined that the transmitter 110 is in the state of hoveringor not.

Please refer to FIG. 9F, which shows a timing sequence of signalmodulation in accordance with an embodiment of the present invention.The modulation shown in FIG. 9F may apply to the transmitter 110 shownin FIG. 5. In the embodiment shown in FIG. 9E, no proportional relationis defined over lengths of the R, T0, and T1 periods. Instead, in theembodiment shown in FIG. 9F, the ratios between lengths of the R, T0,and T1 periods is 1:2:4. Assuming that the touch sensitive processingapparatus 130 could perform N sampling during one time unit, where N isa positive integer. Hence, touch sensitive processing apparatus 130could perform N, 2N , and 4N samplings during the R, T0, and T1 periods,respectively. The present invention does not limit the ratios betweenthe lengths of these three periods. In one instance, the period with themost powerful electric signal endures the shortest time; the period withthe weakest electric signal endures the longest time. For examples, theratios may be 1:3:2, 1:2:3, or etc. The design of ratios depends on theimplementation. Although the paragraphs above enumerate modulations intwo periods T0 and T1 merely, the present invention does not limit tothat. More periods is applicable to the present invention.

In one embodiment, the transmitter 110 could transmit stronger electricsignals in the state of hovering and transmit weaker electric signals inthe state of touching. Consequently, it increases the chance for thetouch sensitive processing apparatus 130 detects the transmitter 110hovering above the touch panel 120. When the transmitter 110 contactsthe touch panel 120, it further reduces the power consumption of thetransmitter 110.

For examples, in the embodiments shown in FIG. 9C and 9 D, when the tipsection 230 is not touched, the electric signal emitted during the Rperiod is stronger than the electric signal emitted during the L1 periodwhich corresponding to the T0 and T1 periods.

The signal modulation represents that the transmitter 110 is in thestate of hovering. In such state, the signal frame the transmitter 110emits electric signal contains only one R period. During this R period,both the ring electrode 550 and the tip section 230 transmit theelectric signals concurrently. In one embodiment, the electric signalsmay be come from the same signal source and having the same frequencyand/or modulation. In one instance, both the ring electrode 550 and thetip section 230 transmit signals from the third signal source 513.Alternatively, the ring electrode 550 and the tip section 230 maytransmit signals from the first, second, and third signal sources 211,212, and 513. Hence the electric signal emitted during the R period isthe sum of output powers of these three signal sources.

In the Table 1 embodiment shown in FIG. 9A, when the transmitter 110 inthe state of hovering, output power come from the first signal source211 and the second signal source 212 . In the Table 2, when thetransmitter 110 in the state of touching, output power come from one offirst signal source 211 and the second signal source 212 during the T0and T1 periods. Hence, the transmitter 110 emits stronger electricsignal if the tip section is not touched and emits weaker electricsignal if the tip section is pressed.

Similarly, in the Table 3, the transmitter 110 utilizes output powerfrom both the first signal source 211 and the second signal source 212in the state of hovering. Instead, in the Table 4, the transmitter 110makes use of one of the first signal source 211 and the second signalsource 212 during the T0 and T1 periods. Hence, the transmitter 110emits stronger electric signal if the tip section is not touched andemits weaker electric signal if the tip section is pressed.

The reason for adding noise detection period in the embodiments shown inFIG. 9A through 9F is described below. Please refer to FIG. 10, whichshows noise propagation path in accordance with an embodiment of thepresent invention. As shown in FIG. 10, the electronics 100 includingthe touch panel 120 emits noise signals with frequency f0, which is amember of frequency group F0. It is assumed that the frequency group F0contains another member frequency f3. When user holds the electronics100, the noise with frequency f0 would propagate to the touch panel 120via the user's finger. If no noise detection is performed, the touchpanel 120 may take the noise with frequency f0 from the finger as theelectric signal emitted by the transmitter 110. Hence, if the noise withfrequency f0 could be detected in advanced, it could be filtered outfrom the signal frame.

In case the transmitter 110 is capable to change frequency, it canautomatically transmit signal with another member frequency f3 of thefrequency group F0 if the noise with frequency f0 is detected.Consequently, during the periods of signal frame, the touch sensitiveprocessing apparatus 130 detects signal with frequency f3 from thetransmitter 110 and noise signal with frequency f0 from the finger. Thisconfuses the touch sensitive processing apparatus 130. Therefore it canperform a noise detection after the T1 period or the signal frame as theembodiment shown in FIG. 9B. At this moment, since the transmitter 110ceases transmitting signals with frequency f3 while the noise signalwith frequency f0 from the finger and the touch panel 120 stands still,it could be determined by the touch sensitive processing apparatus 130that the signal with frequency f3 detected during the time frame is thesignal came from the transmitter 110.

It is mentioned in the description related to FIG. 2 that the signalstrength ratio is changed according to impedance variation of the firstcomponent 221. Please refer to FIG. 11, which depicts a structurediagram of a first capacitor 221 in accordance with an embodiment of thepresent invention. By changing the impedance of the first capacitor 221to adjust the signal strength ratio of multiple frequencies. Traditionalcapacitor is formed by two plates of conducting metal. The capacitance Cis proportional to the permittivity and the plate areas and inverselyproportional to the distance between these two plates.

One aspect of the embodiment is to use a mechanic structure fortransforming a displacement along the axis of the transmitter 110 toanother displacement vertical or angled to the axis. By creating thedisplacement, the capacitance and first impedance Z1 of the firstcapacitor 221 are changed accordingly while keeps the capacitance andsecond impedance Z2 of the second capacitor 222 intact, such that theratio between the signal strength M1 with first frequency (group) andthe signal strength M2 with second frequency (group).

There exist three non-contacting metal plates shown in FIG. 11. Thefirst capacitor 221 is formed by a first metal plate 1110 and a secondmetal plate 1120. The second capacitor 222 is formed by the second metalplate 1120 and a third metal plate 1130. In one instance, the firstmetal plate 1110 is formed on a flexible circuit board or printedcircuit board which covers with insulating paint or dielectric plate.The second metal plate 1120 and the third metal plate 1130 are formed inthe double sides of the same circuit board or printed circuit boardwhich also covers with insulating paint or dielectric plate. The secondmetal plate 1120 is coupled to the fore-end tip section 230 throughwiring. The tip is attached to a lifting element 1140 (e.g. the rampmeans). A movement of the tip can directly or indirectly deform whole orpart of the first metal plate 1110 (and flexible circuit board or PCB)such that a displacement vertical to along the axis of the transmitter110 or stylus is created accordingly.

The first metal plate 1110 is supplied with electric signal with firstfrequency (group) and the third metal plate 1130 is supplied withelectric signal with second frequency (group). Therefore current inducedin the second metal plate 1120 generates signals with the firstfrequency (group) and the second frequency (group) which is sent to thetouch panel 120 via the fore-end tip section 230. When the tip section230 is not pressed, the first metal plate 1110 and its circuit board donot have a displacement vertical to the axis of the transmitter 110.However, when the tip section 230 is pressed, the ramp means 1140transforms the force parallel to the axis to the direction vertical tothe axis such that the circuit board of the first metal plate 1110deforms and moves. Furthermore, the permittivity of the first capacitor221 changes accordingly, so do the capacitance C1 and impedance Z1 ofthe first capacitor 221. When the tip section 230 is pressed, thecircuit board of the second metal plate 1120 and the third metal plate1130 moves as a whole. Therefore the capacitance C2 and impedance Z2 ofthe second capacitor 222 remains the same.

Since the circuit board of the first metal plate 1110 deforms upward,the embodiment may include at least one supporting element 1150 toprovide support downward for helping the circuit board of the firstmetal plate 1110 recover to the original shape after the pressure to thetip section 230 is dismissed. When the circuit board is not deformed,the supporting force provided by the supporting element may be zero.

In one example of the present embodiment, the capacitances of the firstcapacitor 221 and the second capacitor 222 may equals. If so, thepermittivity, distance, and area of these two capacitors are the same.However, the present invention does not limit to the condition. It onlyrequires that the touch sensitive processing apparatus 130 is knownabout the impedance ratio between these two capacitors of thetransmitter 110.

In this embodiment, expensive force sensing resistor is replaced bycheaper circuit board or PCB. Besides, if the capacitances of the firstcapacitor 221 and the second capacitor 222 are designed to be equal,permittivity of these two capacitors 221 and 222 would be varied in thesame rate due to environmental change. Hence the default ratio could bemaintained consequently. Besides, it does not require any activecontrolling component to adjust the ratio of these two impedances Z1 andZ2. The transmitter 110 could provide electric signal passively. So manyresources could be saved.

Please refer to FIG. 12, which shows a diagram of reduced embodimentshown in FIG. 11. The circuit board, supporting element 1150, and thewiring between the second metal plate 1120 and the tip section 230 areomitted. The description of embodiment shown in FIG. 12 can referencethose for FIG. 11.

Please refer to FIG. 13, which is a variation of the embodiment shown inFIG. 12. The third metal plate 1130 is moved to the aft of the firstmetal plate 1110 and they are not electrically coupled. When the tipsection 230 is pressed, only the first metal plate 1110 and its circuitboard deform. In some examples, the first metal plate 1110 and the thirdmetal plate 1130 may be formed on the same circuit board.

Please refer to FIG. 14, which is a variation of the embodiment shown inFIG. 13. The first metal plate 1110 and the third metal plate 1130comprise two plates A and B, respectively. They are feed into signalswith first frequency (group) and second frequency (group), respectively.When the tip section 230 is pressed, the first metal plate A 1110A, thefirst metal plate B 1110B, and their circuit board deforms, but thethird metal plate A 1130A, the third metal plate B 1130B, and theircircuit board do not deform. Comparing with the embodiment shown in FIG.13, since there are two deforming metal plates 1110A and 1110B, theimpedance variation would be larger and more obvious than the variationof the embodiment shown in FIG. 13.

Please refer to FIG. 15, which is a variation of the embodiment shown inFIG. 14. The second metal plate 1120 also comprise two plate A 1120A andplate B 1120B, which are coupled to the tip section 230 through wiring.A first capacitor A 221A is formed by the first metal plate A 1110A andthe second metal A 1120A. A second capacitor A 222A is formed by thesecond metal plate A 1120A and the third metal plate A 1130A. A firstcapacitor B 221B is formed by the first metal plate B 1110B and thesecond metal B 1120B. A second capacitor B 222B is formed by the secondmetal plate B 1120B and the third metal plate B 1130B. When the tipsection is pressed, the first metal plate A 1110A, the first metal plateB 1110B, and their circuit boards deform. However, the third metal plateA 1130A, the third metal plate B 1130B, and their circuit boards remainsthe same. Comparing with the embodiment shown in FIG. 13, since thereare two deforming metal plates 1110A and 1110B, the impedance variationwould be larger and more obvious than the variation of the embodimentshown in FIG. 13.

Please refer to FIG. 16A, which shows a structure in accordance with anembodiment of the present invention. In the embodiment shown in FIG.16A, there are a first metal plate 1110, a second metal plate 1120, anda third metal plate 1130 from top to bottom. The first metal plate 1110and the third metal plate 1130 are fixed and fed in signals with firstfrequency (group) and second frequency (group), respectively. Currentinduced from the second metal plate 1120 generates electric signalsmixed with first frequency (group) and second frequency (group).

A first capacitor 221 is formed by the first metal plate 1110 and thesecond metal plate 1120. A second capacitor 222 is formed by the secondmetal plate 1120 and the third metal plate 1130. When the second metalplate 1120 is not deformed, the impedances of the first capacitor 221and the second capacitor 222 are fixed in the same environment. Hence astrength ratio of signal with first frequency (group) and signal withsecond frequency (group) contained in the electric signal could becalculated. If the ratio is a predetermined value or falls into apredetermined range, it is concluded that the second metal plate 1120 isnot deformed.

If the second metal plate 1120 deforms, the impedances and capacitancesof the first capacitor 221 and the second capacitor 222 changeaccordingly. In consequence, a strength ratio could be calculatedaccording to these two signal strength values. Based on the variation ofthe ratio, the deforming and displacement of the second metal plate 1120could be calculated. Steps shown in the embodiment of FIG. 6 could beapplicable here.

Please refer to FIG. 16B, which is a variation of the embodiment shownin FIG. 16A. The second metal plate 1120 and the third metal plate 1130are fixed and fed in signals with first frequency (group) and secondfrequency (group), respectively. Current induced from the first metalplate 1110 generates electric signals mixed with first frequency (group)and second frequency (group).

A first capacitor 221 is formed by the first metal plate 1110 and thesecond metal plate 1120. A second capacitor 222 is formed by the firstmetal plate 1110 and the third metal plate 1130. When the first metalplate 1110 is not deformed, the impedances of the first capacitor 221and the second capacitor 222 are fixed in the same environment. Hence astrength ratio of signal with first frequency (group) and signal withsecond frequency (group) contained in the electric signal could becalculated. If the ratio is a predetermined value or falls into apredetermined range, it is concluded that the first metal plate 1110 isnot deformed.

If the first metal plate 1110 deforms, the impedances and capacitancesof the first capacitor 221 and the second capacitor 222 changeaccordingly. In consequence, a strength ratio could be calculatedaccording to these two signal strength values. Based on the variation ofthe ratio, the deforming and displacement of the first metal plate 1110could be calculated. Steps shown in the embodiment of FIG. 6 could beapplicable here. The impedance may be changed according to variations oftemperature and humanity. However, both impedances of the firstcapacitor 221 and the second capacitor 222 change together according tothe environmental variations of temperature and humanity. Therefore,influence on the ratio caused by temperature and humanity could bereduced or eliminated.

Please refer to FIGS. 17A and 17B, which show structural diagrams of thefirst capacitor and the second capacitor in accordance with anembodiment of the present invention. In the embodiment shown in FIGS.16A and 16B, signals with first frequency (group) and second frequency(group) are fed. However, in the embodiment shown in FIGS. 17A and 17B,a driving signal with the same frequency is fed. In other words, theembodiments can be applicable to those embodiments shown in FIGS. 7Athrough 7D. The driving signal fed in could be the signal source 714 ofthe embodiments shown in FIGS. 7A and 7B. The electric signal from thetransmitter wired communication unit 771 of the embodiment shown in FIG.7C could be the signal source. Moreover, the electric signal receivedfrom the first electrodes 121 and/or the second electrodes 122 of thetouch panel when the tip section 230 shown in FIG. 7D approximates ortouches could be used as the signal source.

The structure of three metal plates as shown in FIG. 17A is identical tothe structure of three metal plates as shown in FIG. 16A. A drivingsignal with a frequency may feed into the deformable second metal plate1120. Due to capacitive effect between the second metal plate 1120, thefirst metal plate 1110 outputs the induced current with a current valueI1. Analogously, Due to capacitive effect between the second metal plate1120, the third metal plate 1130 outputs the induced current with acurrent value I2.

A first capacitor 221 is formed by the first metal plate 1110 and thesecond metal plate 1120. A second capacitor 222 is formed by the secondmetal plate 1120 and the third metal plate 1130. When the second metalplate 1120 is not deformed, the impedances of the first capacitor 221and the second capacitor 222 are fixed. Hence, the current values I1 and12 are analyzed and a ratio is calculated according to these two currentvalues. When the ratio is a predetermined value or falls into apredetermined range, it is determined that the second metal plate 1120is not deformed.

When the second metal plate 1120 is deformed, the impedances andcapacitance of the first capacitor 221 and the second capacitor 222 arechanged. Hence, a ratio is calculated according to these two currentvalues. Based on the variation of the ratio, the deforming anddisplacement of the second metal plate 1120 could be deduced inconsequence. The embodiment shown in FIG. 8 could be applicable here.

Please refer to FIG. 17B, which is a variation of the embodiment shownin FIG. 17A. The second metal plate 1120 and the third metal plate 1130are fixed. The driving signal with a frequency is fed into thedeformable first metal plate 1110. Due to capacitive effect between thefirst metal plate 1110, the second metal plate 1120 outputs the inducedcurrent with a current value I1. Analogously, Due to capacitive effectbetween the first metal plate 1110, the third metal plate 1130 outputsthe induced current with a current value I2.

A first capacitor 221 is formed by the first metal plate 1110 and thesecond metal plate 1120. A second capacitor 222 is formed by the firstmetal plate 1110 and the third metal plate 1130. When the first metalplate 1110 is not deformed, the impedances of the first capacitor 221and the second capacitor 222 are fixed. Hence, the current values I1 andI2 are analyzed and a ratio is calculated according to these two currentvalues. When the ratio is a predetermined value or falls into apredetermined range, it is determined that the first metal plate 1110 isnot deformed.

When the first metal plate 1110 is deformed, the impedances andcapacitance of the first capacitor 221 and the second capacitor 222 arechanged. Hence, a ratio is calculated according to these two currentvalues. Based on the variation of the ratio, the deforming anddisplacement of the first metal plate 1110 could be deduced inconsequence. The embodiment shown in FIG. 8 could be applicable here.

Please refer to FIG. 18, which is a variation of the embodiment shown inFIG. 11. The embodiment shown in FIG. 11 requires feeding signals withtwo different frequencies. Instead, in the embodiment shown in FIG. 18as well as those shown in FIGS. 17A and 17B, it is required to feeddriving signal with a frequency or some kind of signal, merely. Nomatter how many frequencies contained in the signal fed in.

A first capacitor 221 is formed by the first metal plate 1110 and thesecond metal plate 1120. A second capacitor 222 is formed by the secondmetal plate 1120 and the third metal plate 1130. Since the distance andpermittivity between the second metal plate 1120 and the third metalplate 1130, the capacitance and impedance of the second capacitor 222 isfixed. When the first metal plate 1110 is not deformed, the impedancesof the first capacitor 221 and the second capacitor 222 are fixed.Hence, a ratio of analyzed current value I1 and I2 could be calculated.When the ratio is a predetermined value or falls into a predeterminedrange, it is determined that the first metal plate 1110 is not deformed.Moreover, the deforming of the first metal plate 1110 changes its owncapacitance and impedance. Thus when it is deformed due to externalforce, the current value I1 is changed accordingly. In consequence, theratio involving the current values I1 and I2 also changes. Based on thevariation of the ratio, the deforming and displacement of the firstmetal plate 1110 could be deduced in consequence. The embodiment shownin FIG. 8 could be applicable here.

In alternative embodiment of the present invention, the controller orcircuit of the transmitter 110 may feed driving signal with a frequencyinto the second metal plate 1120 and calculate the current values I1 andI2 through the first capacitor 221 and the second capacitor 222,respectively. By using the ratio of these two current values, a sensingvalue of pressure level of the tip section is deduced accordingly. Inother words, utilizing the mechanism including the first impedance Z1and the second impedance Z2, the present invention provides a design ofFSC, force sensing capacitor, which may replace traditional forcesensing components, such as FSR (force sensing resistor), for detectingpressure level. The FSC provided by the present invention hascharacteristics such as low cost and immune to influence of temperatureand humanity. As shown in the figures above, FSC utilizing flexible PCBis disclosed by present invention. One aspect of the present applicationis to provide novel forms of FSC.

Please refer to FIG. 19A, which depicts a profiling diagram of the FSCstructure used in the transmitter 110 in accordance with an embodimentof the present invention. Please be noted that scales of FIGS. 19Athrough 19E are changed to highlight some important parts. Besides, somefixed components are omitted for simplifying the figure. As shown inFIG. 19A, the most left component is a long rod tip or the tip section230, which is a conductor. For convenience, the tip section is at thefore end of the transmitter 110 or active stylus. When the tip sectioncontacts the fore moving part 1971, the tip section 230 is electricallycoupled to the fore moving part 1971. The fore-moving part 1971 could bejoined together with a rear moving part 1972 by protruding fasteners inthe middle of the fore moving part 1971 and corresponding recessedfasteners in the middle of the rear moving part 1972. In one embodiment,the protruding and recessed fasteners comprise screw thread or whorl.Both the fore and rear moving parts 1971 and 1972 may be conductors orconductive elements, such as metal.

A shell component 1980, shown in FIG. 19A, circularly embraces the foreand rear moving parts 1971 and 1972. Only parts of the shell component1980 are illustrated in FIG. 19A. A neck part with smaller diameter ofthe shell component 1980 is constructed nearby the tip section 230. Ashoulder part with larger diameter next to the neck part of the shellcomponent is used to be a bearing part. As shown in FIG. 19A, at leastone elastic element 1978 is placed between the bearing part and the foremoving part 1971. The elastic element 1978, such as spring, elasticpiece, or in any other forms, is supposed to provide force between theshell component 1980 and the fore moving part 1971 along the axis of thestylus. In some embodiments, the elastic element 1978 unlike the oneshown in FIG. 19A is surrounded the moving part 1970 and the neck partof the shell component 1980.

In another embodiment, the elastic element 1978 may provide force toboth the shell component 1980 and the rear moving part 1972 along theaxis of the stylus. Because a whole moving part 1970 composed of thefore and the rear moving parts 1971 and 1972 by fasteners, no matterwhich one of the fore and the rear moving part 1971 and 1972 is pressed,the whole moving part 1970 is pushed to the tip and the tip section 230is also pushed forward accordingly.

In case the tip section 230 is pressed toward the right hand side ofFIG. 19A or toward the rear, the force provided by the elastic element1978 is compromised and the elastic element 1978 would be compressedsuch that a portion of the moving part 1970 touches the bearing part ofthe shell component 1980. Hence, the design provided by the presentapplication creates a stroke that moving part 1970 moves inside the neckpart of the shell component 1980 along the axis of the stylus.Accordingly, the tip section 230 touching the moving part 1970 alsomoves the same distance of the stroke along the axis. The distance ofthe stroke could be varied according to different designs, e.g., 1 mm or0.5 mm. The present invention does not limit the distance of the stroke.

In the rear of the rear moving part 1972, a dielectric film 1973 isformed. In the rear of the dielectric film 1973, a compressibleconductor 1974 is arranged. In one embodiment, the compressibleconductor 1974 may be a conductive rubber or an elastic element formedby conductors. A sandwich structure comprising the moving part 1970, thedielectric film 1973, and the compressible conductor 1974 makes acapacitor or a FSC. The FSC provided by the present invention may beapplicable to the first capacitor 221 shown in FIG. 2 through FIG. 5. Inshort, the FSC disclosed in the present application could be used in theembodiments.

The compressible conductor 1974 is attached to a conductor base 1975which is further attached to an inner face of the shell component 1980by fasteners. In case the moving part 1970 moves toward rear side orright hand side, the compressible conductor 1974 is compressed by therear moving part 1972 because the conductor base 1975 is fixed. Thus thecapacitance of the FSC is changed accordingly.

Because of the restriction of stylus shape, circuits and battery modulemay be placed in the rear of the conductor base 1975. As shown in FIG.19A, those components are represented by a PCB 1990. As a first plate ofthe FSC, the moving part 1970 is connected to the PCB through a movingpart wire 1977. As a second plate of the FSC, the conductor base 1975 isconnected to the PCB 1990 through a base wire 1976.

The base wire 1976 may be another elastic element. In some embodiments,the base wire 1976, unlike the one shown in FIG. 19A, is surrounded theconductor base 1975. In other embodiments, the conductor base 1975 isnot conductive. Hence the base wire 1976 is electrically coupling to thecompressible conductor 1974 through the conductor base 1975.

In one embodiment, the manufacturing method of the dielectric film 1973is submerging the right hand side surface of the rear moving part 1972in a dielectric liquid. After the liquid stayed on the surface dried, adielectric film 1973 is naturally formed on the right hand side surfaceof the rear moving part 1972.

Please refer to FIG. 20, which shows a profiling diagram of contactsurface of the compressible conductor 1974 facing the dielectric film1973. The figure depicts four embodiments of the contact surface of thecompressible conductor 1974 facing the dielectric film 1973. Theembodiment (a) shows a surface having a central bulge. The embodiment(c) shows a sloped surface. The embodiment (b) shows a conical surface.And the embodiment (d) illustrates a surface with multiple protrudingbulges. The present application does not limit to the surfaces shown inthose embodiments.

Although the surface attaching the dielectric film 1973 of the movingpart 1970 is a plane surface, the present invention does not limit tothat. The surface may be constructed as the surfaces shown in FIG. 20,such as having a central bulge, having multiple bulges, sloped, orconical. In other words, both the surfaces of the compressible conductor1974 and the dielectric film 1973 are not planes in some embodiments.

Please refer to FIG. 19B, which shows an assembled profiling diagram ofthe structure shown in FIG. 19A. In the assembled structure, a singlewhole moving part 1970 is formed by the fore and the rear moving part1971 and 1972. The moving part 1970 and the bearing of the shellcomponent 1980 are connected by the elastic element 1978. The elasticforce provide by the elastic element 1978 pushes the moving part 1970toward and touches the tip section 230 until portion of the bearing ofthe shell component 1980 is touched by the rear moving part 1972. Astroke d of the moving part 1970 is relative to the shell component1980. In this situation, the compressible conductor 1974 is not deformedor compressed. It is assumed that a first capacitance value provided bythe FSC.

Please refer to FIG. 19C, which shows another assembled profilingdiagram of the structure shown in FIG. 19A. Comparing with FIG. 19B, thetip section 230 is pressed toward the rear side. Influenced by themovement of the tip section 230, the moving part 1970 overcomes theforce provided by the elastic element 1978 and moves the whole distanceof the stroke d until the fore moving part 1971 touches the bearing ofthe shell component 1980. In this situation, the compressible conductor1974 is compressed by the moving part 1970 and the dielectric film 1973and deformed. It is assumed that a second capacitance value provided bythe FSC is different to the first capacitance value.

Between the positions shown in FIGS. 19B and 19 C, countless positionsthe moving part 1970 can stay. In other words, there exist countlesscompressible levels of the compressible conductors 1974. Or the area ofcontact surface between the compressible conductor 1974 and thedielectric film 1973 could be varied indefinitely. Each of thepositions, the compressed levels, or the areas can be corresponding to aparticular capacitance value of the FSC.

Please refer to FIG. 19D, which depicts a profiling diagram of the FSCstructure used in the transmitter 110 in accordance with an embodimentof the present invention. Comparing to FIG. 19B, the difference is thatthe compressible conductor 1974 and the dielectric film 1973 exchangetheir positions. Nevertheless, in case the moving part 1970 moves to therear side, the compressible conductor 1974 is compressible by thedielectric film 1973 and deformed. The capacitance value of the FSC ischanged accordingly.

Please refer to FIG. 19E, which depicts a profiling diagram of the FSCstructure used in the transmitter 110 in accordance with an embodimentof the present invention. Comparing with FIG. 19B, the differencesinclude that a compressible dielectric material 1979 rather than thedielectric film 1973 is place in the right hand side of the rear movingpart 1972. The compressible dielectric material 1979 may be dielectricrubber, plastic, foam or etc. The conductor attached to the conductorbase 1975 is replaced by an incompressible conductor such as metal orgraphite. When pressed by the moving part 1970, the thickness of thecompressible dielectric material 1979 decreases, the distance betweenthe moving part 1970 and the conductor also decreases consequently.Hence the capacitance of the FSC is changed accordingly. However, thecost of the incompressible conductor shown in FIG. 19E is more expensivethan the compressible conductor shown in FIG. 19A.

In a variation of the embodiment shown in FIG. 19E, the contact surfaceof the conductor facing the compressible dielectric material 1979 mayadopt those shown in FIG. 20. In another variation, the contact surfaceof the compressible dielectric material 1979 facing the conductor mayadopt those shown in FIG. 20.

Similar to the embodiment shown in FIG. 19D, the positions of thecompressible dielectric material 1979 and the conductor may be exchangedsuch that the compressible dielectric material 1979 is attached to theconductor base 1975 and the conductor is attached to the rear of themoving part 1970. When the moving part 1970 moves to the rear side, theconductor causes the compressible dielectric material 1979 deformed suchthat the capacitance of the FSC is changed accordingly.

Please refer to FIG. 21, which illustrates a pressure sensor accordingto an embodiment of the present invention. As shown in the figure, thepressure sensor 2110 has two input terminals a and b and an outputterminal c, which are all connected to a control unit 2120. The controlunit 2120 feeds signals with first frequency (group) F1 and secondfrequency (group) F2 into the input terminals a and b, respectively, andreceives the output signal of the pressure sensor 2120. The control unit2120 may embody the method disclosed in FIG. 6.

When external pressure makes capacitance change of a capacitor C1, thecontrol unit 2120 could deduce the pressure according to the capacitancechange. Hence, the pressure sensor 2110 could be widely adapted topressure measure devices such as weight sensor. In one application, thepressure sensor 2120 could be used in another form of stylus. After thepressure on the tip of the stylus is deduced, the control unit 2120drives a signal transmitter for transmitting an electric signal with apredetermined frequency f0 to a touch panel.

It is mentioned that the transmitter 110 may transmit the electricsignal at some time after receiving the beacon signals emitted from thetouch panel 120, such that the touch panel 120 could detect the positionof the transmitter 110 as well as the sensor states of the transmitter110. If no beacon signal is received during a first period, thetransmitter 110 may enter a power saving mode. In this mode, thetransmitter 110 detects the beacon signal every detection period. Oncethe beacon signal is detected, the transmitter 110 recovers back tonormal working mode. The detection period is longer than thetransmission period of the beacon signal.

Moreover, if no beacon signal is received during a second period in thepower saving mode, the transmitter 110 may enter a sleep mode to turnoff circuits and most parts until being waked up. In one embodiment ofthe present invention, in the sleep mode, the receiving circuit of thebeacon signal and the transmitter of the electric signal of thetransmitter 110 are turned off. A button or a switch of the transmitter110 could be used to wake itself up by user. In another embodiment ofthe present application, examples shown in FIGS. 23A, 23B, 24A and 24Bcould be used to wake up the transmitter 110. After the tip section 230touches object, the voltage level of a connection port or GPIO1 israised to high from low such that the transmitter 110 begins to transmitelectric signals.

In the present application, one function of the ring electrode 550 is toreceive the beacon signal in additional to the tip section 230. Sincethe surface area and volume of the ring electrode 550 is larger than thetop of the tip section 230, it can receive the beacon signal distantaway from the touch panel. Or the touch panel 120 may transmit weakerbeacon signal to save power consumption. If no beacon signal is receivedfor a while, active stylus may enter deeper sleep mode to save morepower. When in this sleep mode, user may recover the transmitter 110back to the normal working mode by pressing the tip section 230.Examples shown in FIGS. 23A, 23B, 24A and 24B could be used to wake upthe transmitter 110. After the tip section 230 touches object, thevoltage level of a connection port or GPIO1 is raised to high from lowsuch that the transmitter 110 begins to transmit electric signals.

When multiple transmitters 110 operate on one touch panel 120, the touchpanel 120 could transmit different beacon signals for correspondingtransmitter 110 to emit its electric signal. The transmitter 110 mayadjust the signal frequency or modulation of the first signal source211, the second signal source 212, and the third signal source 513 suchthat the touch panel 120 could distinguish the source transmitter 110 ofthe received electric signals. Analogously, the different beacon signalsmay have different frequencies or different modulations.

Please refer to FIG. 22, which illustrates a pressure sensor accordingto an embodiment of the present invention. In this embodiment, thecontrol unit 2220 may feed driving signal with a frequency to an inputterminal c of the pressure sensor 2210 and receive currents with currentvalues I1 and I2 corresponding to a first capacitor C1 and a secondcapacitor C2, respectively. A ratio of these two current values iscalculated by the control unit 2220. Therefore a pressure level could bededuced accordingly. The control unit 2220 may embody the method shownin FIG. 8. In one application, the driving signal with the frequency isfed externally into the input terminal c of the pressure sensor 2220.

Please refer to FIGS. 23A and 23B, which depict profiling diagrams of aswitch structure in accordance with an embodiment of the presentinvention. In the embodiment shown in FIG. 23A, there are three circuitboards. As seen in previous figures, there is a ramp at the right handside. Before the ramp pushes to left, a first contact point p1 of theupper circuit board is coupled to a voltage source Vdd and a firstconnection port (GPIO1). If no displacement vertical to the axis of thestylus, the first contact point p1 is contacted with a second contactpoint p2 on the middle circuit board. There is also a third contactpoint p3 on the middle circuit board coupled to the second contact pointp2. A fourth contact point p4 of the lower circuit board is coupled to aground level and a second connection port (GPIO2). Besides, the fourthcontact point p4 is electrically coupled to the third contact point p3.There is a resistor between the power source Vdd and the firstconnection port (GPIO1). If the circuit between the upper and the middlecircuit boards is shorted, i.e., the first contact point pl contactswith the second contact point p2, and the circuit between the middle andlower circuit boards is shorted, i.e., the third contact point p3contacts with the fourth contact point p4, the voltage level of thefirst connection port (GPIO1) is low or ground.

Please refer to FIG. 23B, after the ramp is pressed, the movement of theramp deforms the contacting parts of the upper and the lower circuitboards. Due to the deformations, the circuit between the upper and themiddle circuit boards is open, i.e., the first contact point p1separates with the second contact point p2, and the circuit between themiddle and lower circuit boards is open, i.e., the third contact pointp3 separates with the fourth contact point p4, the voltage level of thefirst connection port (GPIO1) is high or as high as Vdd.

In response to the voltage level of the first connection port (GPIO1)from low to high, the transmitter 110 in sleep mode is waked up. Alreadyseen in previous figures, supporting elements corresponding to the upperand the lower circuit boards help to recover these two circuit boards'position, respectively, if the pressure of the ramp disappears. At thismoment, the voltage level of the first connection turns to low fromhigh. The first and the second connection ports may be pins of processorin the transmitter 110.

Please refer to FIGS. 24A and 24B, which depict profiling diagrams of aswitch structure in accordance with an embodiment of the presentinvention. The embodiment shown in FIGS. 23A and 23B has two potentialopenings. No matter which opening is open, it turns the voltage level ofthe first connection to high from low. However, the embodiment shown inFIGS. 24A and 24B, only one potential opening is presented. The circuitalong the middle circuit board connects to ground. In case the circuitbetween the upper and the middle circuit board is shorted, the voltagelevel of the first connection port is low or ground. Instead, if thecircuit between the upper and the middle circuit board is open, thevoltage level of the first connection port is high or as high as Vdd. Inthe embodiment shown in FIGS. 24A and 24B, the second contact point p2is electrically coupled to the second connection port (GPIO2).

Please refer to FIG. 25, which shows a diagram for calculating the tipposition. There are two transmitters 110 shown in FIG. 25, both includethe ring electrode 550 and the tip section 230. The left-hand sidetransmitter 110 is perpendicular to the touch panel 120, the angle isapproaching or equals to 90 degree. The angle between the right-handside transmitter 110 and the touch panel 120 is less than 90 degree.Moreover, a transparent surface layer of the touch panel 120 has athickness. Normally, the transparent surface layer is a reinforcedglass. A display layer is underneath the transparent surface layer.

Since the transmitters 110 emits electric signals via the ring electrode550 and/or the tip section 230 during the time period R, the touchsensitive processing apparatus 130 could calculate a centroid positionR_cg of the electric signals which is corresponding to a centroidposition of the ring electrode 550 and/or the tip section 230 projectingto the touch panel 120. After that, during the time periods T0 and T1,transmitter 110 emits electric signals only via the tip section 230.Similarly, the touch sensitive processing apparatus 130 could calculatea centroid position Tip_cg of the electric signals which iscorresponding to a centroid position of the tip section 230 projectingto the touch panel 120.

For the left-hand side transmitter 110 shown in FIG. 25, since it isperpendicular to the touch panel 120, the position R_cg equals or isapproaching to the position Tip_cg. Thus, a position Tip_surface wheretop of the tip section 230 touches the transparent surface layer of thetouch panel 120 equals or is approaching to the positions R_cg andTip_cg. Morevoer, a position Tip_display where the top of the tipsection 230 projecting on the display layer of the touch panel 120equals or is approaching to the positions, R_cg, Tip_cg, andTip_surface.

For the right-hand side transmitter 110 shown in FIG. 25, there exist aninclination angle between the transmitter 110 and the touch panel 120.More distant between the positions R_cg and Tip_cg, the inclinationangle is larger. Depends on the implementations of the transmitter 110,the inclination angle or positions Tip_surface or Tip_display could befound by the touch sensitive processing apparatus 130 via calculating orchecking a look-up table according to the positions R_cg and Tip_cg.

Please refer to FIG. 26, which depicts a flow chart diagram forcalculating the inclination angle in accordance with the presentinvention. The embodiment is applicable to the transmitter 110 having aring electrode 550 shown in FIG. 5. It is also applicable to the signalmodulations shown in FIGS. 9E and 9F. The method could be performed bythe touch sensitive processing apparatus 130 shown in FIG. 1. Theembodiment shown in FIG. 25 could be reference, too.

In step 2610, calculating a first centroid position R_cg according tothe ring electrode 550 and/or the tip section 230 projecting to thetouch panel 120. In step 2620, calculating a second centroid positionTip_cg according to the tip section 230 projecting to the touch panel120. The present invention does not limit the executing order of thesetwo steps 2610 and 2620. Next, in optional step 2630, calculating aninclination angle according to the first and the second centroidpositions R_cg and Tip_cg. In optional step 2640, calculating a positionTip_surface where top of the tip section 230 touches the transparentsurface layer of the touch panel 120 according to the first and thesecond centroid positions R_cg and Tip_cg. In optional step 2650,calculating a position Tip_display where the tip section 230 projectingon the display layer of the touch panel 120 according to the first andthe second centroid positions R_cg and Tip_cg. Not all but at least oneof steps 2630, 2640, and 2650 has to be performed in the embodiment. Andthe present invention does not limit the executing order of these threesteps 2630, 2640, and 2650.

Please refer to FIG. 27, which shows embodiments of how displayinterface reflects strobe according to the inclination angle and/orpressure of the tip section. There exists 5 rows of embodiments (a)through (e) shown in FIG. 27. Each row comprises three examplescorresponding to three inclination angles. The examples of the most leftcolumn are corresponding to which the active stylus is perpendicular tothe touch sensitive panel. The examples of the most right column arecorresponding to an inclination angle larger than another inclinationangle corresponding to the examples of the middle column. The so-calledstroke in the present invention usually refers to a rendering area onthe display by image processing software.

Please be noted that in the embodiment, it is not required to utilizethe embodiment using the ring electrode to calculate the inclinationangle and positions Tip_surface and Tip_display. In one embodiment,other forms of sensor may be installed on the active stylus to measurethe inclination angle. For example, IMU, inertial measurement unit,gyroscope, and accelerometer made by microelectronics technology areconfigured to measure the inclination angle and report it and/or deriveddata to computer system comprising the touch sensitive panel via wiredor wireless communication. Therefore the computer system could implementthe embodiments shown in FIG. 27. The fore-mentioned wired or wirelesscommunication may follow industrial or proprietary standards such asBluetooth or Wireless USB etc.

Now assuming that active stylus touches the touch panel using the samepressure level in those embodiments shown in FIG. 27. In someembodiments, each intersection point of vertical and horizontal linesrepresents the positions Tip_surface corresponding to where top of thetip touches the transparent surface layer of the touch sensitive panel.In other embodiments, each intersection point of vertical and horizontallines represents the positions Tip_cg corresponding to where thecentroid of the tip. Of course, they may represent the locationsTip_display where the tip projecting the display layer of the touchsensitive panel. For convenience, those three positions are collectivelynamed as a representative point, Tip. In other words, the representativepoint Tip may be one of the points, Tip_display, Tip_surface, or Tip_cg.

In the embodiment (a), in response to the increase of the inclinationangle, the stroke shape changes from circle to ellipse. In other words,the distance between two focal points of the ellipse is corresponding tothe inclination angle. The inclination angle increases with the distancebetween two focal points of the ellipse. Center of the ellipse iscorresponding to the representative point Tip.

The difference between the embodiments (b) and (a) is that oneintersection point of the semi-major axis and the ellipse iscorresponding to the representative point Tip. The difference betweenthe embodiments (c) and (a) is that one of the focal point of theellipse is corresponding to the representative point Tip. The differencebetween the embodiments (d), (e), and (a) is that the stroke shapechanges from ellipse to tear drop. Top of the tear drop of theembodiment (d) is corresponding to the representative point Tip.Somewhere from the top toward the end of the tear drop of the embodiment(e) is corresponding to the representative point Tip.

Although shown in FIG. 27, two stroke shapes and different pointscorresponding to the intersection point are enumerated. The presentinvention does not limit the stroke shape and the types of therepresentative point. In addition, in one embodiment, pressure of thetip may control the size of the shape. For example, the pressure may becorresponding to radius of circle or the distance between the focalpoints of the ellipse. In summarized, human-machine interface can changedisplay content according to pressure of the tip and/or inclinationangle of the active stylus.

In additional to change the stroke shape, the pressure of the tip and/orinclination angle of the stylus may be corresponding to differentcommands. For example of 3 dimensional design software, colortemperature, strength, or scope of illuminating source could be changedaccording to the inclination angle. Or in case an object is selected bytouch of the tip, orientation of the selected object could be changedaccording to direction of the inclination angle. Moreover, direction ofthe selected object could be rotated according to the inclination angle.

It is worthy noted that relation of the inclination angle andcorresponding value is not limited as linearly in the present invention.In some embodiments, the relation may be non-linear and could be foundin a lookup table or calculated in the quadratic function.

Please refer to FIG. 28, which depicts other embodiments of how displayinterface reflects strobe according to the inclination angle and/orpressure of the tip. It depicts two embodiments (a) and (b) whichinclude left and right strokes, respectively. The inclination angle ofthe left hand side stroke is zero. The stroke includes five circles C1through C5 with increasing radius. The inclination angle of the righthand side stroke is a non-zero constant. The stroke includes fiveellipses E1 through E5 with increasing major and minor radius. Sizes ofthe ellipses E1 through E5 depends on pressure values of the tip whichare as the same as corresponding circles C1 through C5. In addition,semi-major axes of these ellipses E1 through E5 are 30 degree offhorizontal according to direction of the inclination angle. Thedirection of the inclination angle and the stroke direction aredifferent. In this figure, these two directions are off a 15-degreeangle.

The embodiment (a) shown in FIG. 28 is corresponding to the embodiment(a) shown in FIG. 27, i.e., center of the ellipse is corresponding tothe representative point Tip. Analogously, The embodiment (b) shown inFIG. 28 is corresponding to the embodiment (b) shown in FIG. 27, i.e.,the intersection point between the semi-major axis and the ellipse iscorresponding to the representative point Tip. Could be seen in thesetwo embodiments shown in FIG. 28, under the same pressure level, thestroke shapes are different according to different inclination angles.In consequence, strokes of some soft and flexible tips such as brush penand quill pen could be simulated according to the pressure level andinclination angle.

One aspect of the present application is to provide a transmitter whichcomprises: a first component for receiving signal with a first frequencygroup, wherein a first impedance of the first component changesaccording to a pressure; a second component for receiving signal with asecond frequency group, wherein the second component has a secondimpedance; and a tip section for receiving outputs of the firstcomponent and the second component and transmitting an electric signal,wherein the tip section is used to receive the pressure.

In one embodiment, the second impedance is not changed according to thepressure. Alternatively, the second impedance is changed according tothe pressure, too.

In one embodiment, the transmitter further comprises a third switch anda third component serially connected to the third switch, wherein thefirst component is connected with the third switch and the thirdcomponent in parallel. The transmitter may further comprise a fourthswitch and a fourth component serially connected to the fourth switch,wherein the first component is connected with the fourth switch and thefourth component in parallel.

Alternatively, the transmitter further comprises a third switch and athird component serially connected to the third switch, wherein thesecond component is connected with the third switch and the thirdcomponent in parallel. The transmitter may further comprise a fourthswitch and a fourth component serially connected to the fourth switch,wherein the second component is connected with the fourth switch and thefourth component in parallel.

In one embodiment, the first frequency group comprises one or more firstfrequency, the second frequency group comprises one or more secondfrequency. The first frequency is different from the second frequency.

In one embodiment, the first impedance equals to the second impedance ifthe pressure is absent. In one embodiment, the tip section does nottouch anything if the pressure is absent.

In one embodiment, a ratio of a first signal strength M1 correspondingto signal with the first frequency group and a second signal strength M2corresponding to signal with the second frequency group is related tothe pressure. The ratio is one of the followings: M1/M2, M2/M1,M1/(M1+M2), M2/(M1+M2), (M1−M2)/(M1+M2), and (M2−M1)/(M1+M2).

In one embodiment, if the ratio equals or falls into a first range, thepressure is absent. If the ratio equals or falls into a second range,the third switch is shorted and the first component is connected withthe third component in parallel. If the ratio equals or falls into athird range, the fourth switch is shorted and the first component isconnected with the fourth component in parallel. If the ratio equals orfalls into a fourth range, the third switch and the fourth switch areshorted and the first component is connected with the third componentand the fourth component in parallel. Alternatively, if the ratio equalsor falls into a fifth range, the third switch is shorted and the secondcomponent is connected with the third component in parallel. If theratio equals or falls into a sixth range, the fourth switch is shortedand the second component is connected with the fourth component inparallel. If the ratio equals or falls into a seventh range, the thirdswitch and the fourth switch are shorted and the second component isconnected with the third component and the fourth component in parallel.

In one embodiment, the first component is a force sensitive capacitor.The second component is a capacitor.

In one embodiment, the transmitter further comprises a ring electrodesurrounding the tip section. The ring electrode is not electricallycoupled to the tip section. In one embodiment, the ring electrodecomprises one or more separate electrodes.

One aspect of the present application is to provide a transmittingmethod for a transmitter, which comprises a first component, a secondcomponent, and a tip section. The tip section is used to receive theoutputs of the first and the second components. The method compriseschanging a first impedance of the first component according to apressure on the tip section; providing signal with a first frequencygroup to the first component; providing signal with a second frequencygroup to the second component; and transmitting an electric signal fromthe tip section.

One aspect of the present application is to provide a method fordetermining a pressure received by a transmitter, comprises: receivingan electric signal transmitted from the transmitter; calculating a firstsignal strength M1 corresponding to signal with a first frequency groupcontained in the electric signal; calculating a second signal strengthM2 corresponding to signal with a second frequency group contained inthe electric signal; calculating the pressure based on a ratio of thefirst signal strength M1 and the second signal strength M2.

In one embodiment, the step of calculating the pressure may comprisesone of the followings: looking into a lookup table, linearinterpolation, and quadratic curve interpolation

In one embodiment, the method further comprises determining the state ofthe third switch according to the ratio. Alternatively, the methodfurther comprises determining the state of the fourth switch accordingto the ratio.

One aspect of the present application is to provide a touch sensitiveprocessing apparatus for determining a pressure received by atransmitter, comprises: an interface configured to connects to aplurality of first electrodes and a plurality of second electrodes of atouch panel, wherein multiple sensing points are located where theintersections of the first and second electrodes; at least onedemodulator for calculating a first signal strength M1 and a secondsignal strength M2 corresponding to signal with a first frequency groupand signal with a second frequency group contained in the electricsignal, respectively; and a calculating unit for calculating thepressure based on a ratio of the first signal strength M1 and the secondsignal strength M2.

In one embodiment, the calculating unit further determining the state ofthe third switch according to the ratio. Alternatively, the calculatingunit further determining the state of the fourth switch according to theratio.

One aspect of the present application is to provide a touch sensitivesystem for determining a pressure received by a transmitter, comprises:the transmitter, the touch panel; and a touch sensitive processingapparatus, the transmitter comprises: a first component for receivingsignal with a first frequency group, wherein a first impedance of thefirst component changes according to a pressure; a second component forreceiving signal with a second frequency group, wherein the secondcomponent has a second impedance; and a tip section for receivingoutputs of the first component and the second component and transmittingan electric signal, wherein the tip section is used to receive thepressure. The touch panel comprises a plurality of first electrodes anda plurality of second electrodes, wherein multiple sensing points arelocated where the intersections of the first and second electrodes. Thetouch sensitive processing apparatus comprises: an interface configuredto connects to the plurality of first electrodes and the plurality ofsecond electrodes of the touch panel; at least one demodulator forcalculating a first signal strength M1 and a second signal strength M2corresponding to signal with a first frequency group and signal with asecond frequency group contained in the electric signal, respectively;and a calculating unit for calculating the pressure based on a ratio ofthe first signal strength M1 and the second signal strength M2.

One aspect of the present application is to provide a transmitter,comprises: a first component for receiving a signal source, wherein afirst impedance of the first component changes according to a pressure;a second component for receiving the signal source, wherein the secondcomponent has a second impedance; and a control unit for calculating afirst current value I1 and a second current value I2 from the firstcomponent and the second component, respectively, and calculating thepressure according to a ratio of the first current value I1 and thesecond current value I2; and a communication unit for transmitting thepressure value.

In one embodiment, the second impedance is not changed according to thepressure. Alternatively, the second impedance is changed according tothe pressure, too.

In one embodiment, the communication unit comprises a wirelesscommunication unit for transmitting the pressure value. Alternatively,the communication unit comprises a wired communication unit fortransmitting the pressure value.

In one embodiment, the signal source is the wired communication unit. Inone embodiment, the signal source is a signal received from the tipsection.

In one embodiment, the ratio is corresponding to the pressure. The ratiomay be one of the followings: I1/I2, I2/I1, I1/(I1+I2), I2/(I1+I2),(I1−I2)/(I1+I2), and (I2−I1)/(I1+I2).

In one embodiment, the first impedance equals to the second impedance ifthe pressure is absent.

In one embodiment, the transmitter further comprises a third switch anda third component serially connected to the third switch, wherein thefirst component is connected with the third switch and the thirdcomponent in parallel. The transmitter may further comprise a fourthswitch and a fourth component serially connected to the fourth switch,wherein the first component is connected with the fourth switch and thefourth component in parallel. In one embodiment, if the ratio equals orfalls into a first range, the pressure is absent. If the ratio equals orfalls into a second range, the third switch is shorted and the firstcomponent is connected with the third component in parallel. If theratio equals or falls into a third range, the fourth switch is shortedand the first component is connected with the fourth component inparallel. If the ratio equals or falls into a fourth range, the thirdswitch and the fourth switch are shorted and the first component isconnected with the third component and the fourth component in parallel.

Alternatively, the transmitter further comprises a third switch and athird component serially connected to the third switch, wherein thesecond component is connected with the third switch and the thirdcomponent in parallel. The transmitter may further comprise a fourthswitch and a fourth component serially connected to the fourth switch,wherein the second component is connected with the fourth switch and thefourth component in parallel. Alternatively, if the ratio equals orfalls into a fifth range, the third switch is shorted and the secondcomponent is connected with the third component in parallel. If theratio equals or falls into a sixth range, the fourth switch is shortedand the second component is connected with the fourth component inparallel. If the ratio equals or falls into a seventh range, the thirdswitch and the fourth switch are shorted and the second component isconnected with the third component and the fourth component in parallel.

In one embodiment, the control unit further determining the state of thethird switch according to the ratio. Alternatively, the control unitfurther determining the state of the fourth switch according to theratio.

In one embodiment, the communication unit further transmitting the stateof the third switch. Alternatively, the communication unit furthertransmitting the state of the fourth switch.

One aspect of the present application is to provide a transmittingmethod for a transmitter, which comprises a first component, a secondcomponent, and a tip section. The tip section is used to receive theoutputs of the first and the second components. The method compriseschanging a first impedance of the first component according to apressure on the tip section; providing a signal source to the firstcomponent and the second component; and calculating the pressureaccording to a ratio of the first current value I1 and the secondcurrent value I2; and transmitting the pressure value.

One aspect of the present application is to provide a touch sensitivesystem for determining a pressure received by a transmitter, comprises:the transmitter; and a host. The transmitter comprises: a firstcomponent for receiving a signal source, wherein a first impedance ofthe first component changes according to a pressure; a second componentfor receiving the signal source, wherein the second component has asecond impedance; and a control unit for calculating a first currentvalue I1 and a second current value I2 from the first component and thesecond component, respectively, and calculating the pressure accordingto a ratio of the first current value I1 and the second current valueI2; and a communication unit for transmitting the pressure value to thehost. The host comprises a host communication unit for receiving thepressure value.

In one embodiment, the touch sensitive system further comprises a touchpanel and a touch sensitive processing apparatus, wherein the touchsensitive processing apparatus coupled to the touch panel is configuredto detect a position the transmitter is relative to the touch panel andto send the position to the host.

In one embodiment, the control unit further determining the state of thethird switch according to the ratio. Alternatively, the control unitfurther determining the state of the fourth switch according to theratio. In one embodiment, the communication unit further transmittingthe state of the third switch to the host. Alternatively, thecommunication unit further transmitting the state of the fourth switchto the host. In one embodiment, the host communication unit isconfigured to receive the state of the third switch. Alternatively, thehost communication unit is configured to receive the state of the fourthswitch.

One aspect of the present application is to provide a force sensor,comprises a first input terminal for receiving signal with a firstfrequency group; a second input terminal for receiving signal with asecond frequency group; and an output terminal for transmitting anelectric signal, wherein a ratio of a first signal strength M1 and asecond signal strength M2 corresponding to signal with a first frequencygroup and signal with a second frequency group contained in the electricsignal, respectively, is corresponding to a pressure.

In one embodiment, the ratio is one of the followings: M1/M2, M2/M1,M1/(M1+M2), M2/(M1+M2), (M1−M2)/(M1+M2), and (M2−M1)/(M1+M2).

In one embodiment, the force sensor further comprises a third switch. Inone embodiment, if the ratio equals or falls into a first range, thepressure is absent. If the ratio equals or falls into a second range,the third switch is shorted.

Alternatively, the force sensor further comprises a fourth switch. Inone embodiment, if the ratio equals or falls into a third range, thefourth switch is shorted. If the ratio equals or falls into a fourthrange, the third switch and the fourth switch are shorted.

One aspect of the present application is to provide a force sensor,comprises a first output terminal for outputting signal with a firstcurrent value I1; and a second output terminal for outputting signalwith a second current value I2, wherein a ratio of the first currentvalue I1 and the second current value I2 is corresponding to a pressure.

In one embodiment, the ratio may be one of the followings: I1/I2, I2/I1,I1(I1+I2), I2/(I1+I2), (I1−I2)/(I1+I2), and (I2−I1)/(I1+I2).

In one embodiment, the force sensor further comprises a third switch. Inone embodiment, if the ratio equals or falls into a first range, thepressure is absent. If the ratio equals or falls into a second range,the third switch is shorted.

Alternatively, the force sensor further comprises a fourth switch. Inone embodiment, if the ratio equals or falls into a third range, thefourth switch is shorted. If the ratio equals or falls into a fourthrange, the third switch and the fourth switch are shorted.

One aspect of the present application is to provide a force sensor,comprises: a first circuit board containing a first metal plate forreceiving signal with a first frequency group; a second circuit board inparallel with the first circuit board, containing a second metal plateand a third metal plate which are intact, wherein the third metal platefor receiving signal with a second frequency group, whether the secondmetal plate for outputting an electric signal, wherein the second metalplate is in the middle of the first and the third metal plates; and aramp means for bending the first circuit board upward.

One aspect of the present application is to provide a force sensor,comprises: a first circuit board containing a first metal plate foroutputting signal with a first current value I1; a second circuit boardin parallel with the first circuit board, containing a second metalplate and a third metal plate which are intact to each other, whereinthe third metal plate for outputting signal with a second current valueI2, whether the second metal plate for receiving a signal source,wherein the second metal plate is in the middle of the first and thethird metal plates; and a ramp means for bending the first circuit boardupward.

In one embodiment, part of the first metal plate is located in the bentpart of the first circuit board.

In one embodiment, the force sensor further comprises a supportingelement for supporting the first circuit board.

In one embodiment, the first metal plate, the second metal plate, andthe third metal plate are in parallel. Alternatively, the distancebetween the first and the second metal plate equals to the distancebetween the second metal plate and the third metal plate.

In one embodiment, a first capacitor is formed by the first and thesecond metal plates; a second capacitor is formed by the second and thethird metal plates. Alternatively, the impedance of the first capacitorequals to the impedance of the second capacitor if the first circuitboard is not bending.

In one embodiment, both the first and the second circuit boards areprinted circuit boards.

One aspect of the application is to provide a force sensor, comprises afirst circuit board containing a first metal plate and a third metalplate which are intact to each other for receiving signal with a firstfrequency group and signal with a second frequency group, respectively;a second circuit board in parallel with the first circuit boardcontaining a second metal plate for outputting an electric signal; and aramp means for bending the first circuit board upward.

One aspect of the application is to provide a force sensor, comprises afirst circuit board containing a first metal plate and a third metalplate which are intact to each other for outputting signal with a firstcurrent value and signal with a second current value, respectively, asecond circuit board in parallel with the first circuit board containinga second metal plate for receiving a signal source 1; and a ramp meansfor bending the first circuit board upward.

In one embodiment, the force sensor further comprises a supportingelement for supporting the first circuit board.

In one embodiment, the first metal plate is in parallel with the secondmetal plate; the second metal plate is in parallel with the third metalplate. Alternatively, the distance between the first and the secondmetal plate equals to the distance between the second metal plate andthe third metal plate.

In one embodiment, a first capacitor is formed by the first and thesecond metal plates; a second capacitor is formed by the second and thethird metal plates. Alternatively, the impedance of the first capacitorequals to the impedance of the second capacitor if the first circuitboard is not bending.

In one embodiment, both the first and the second circuit boards areprinted circuit boards.

One aspect of the application is to provide a force sensor, comprises afirst circuit board containing a first metal plate and a third metalplate which are intact to each other for receiving signal with a firstfrequency group and signal with a second frequency group, respectively;a second circuit board in parallel with the first circuit boardcontaining a second metal plate for outputting an electric signal; athird circuit board containing a fourth metal plate and a fifth metalplate which are intact to each other for receiving signal with the firstfrequency group and signal with the second frequency group,respectively; and a ramp means for bending the first circuit boardupward and bending the third circuit board downward.

In one embodiment, the force sensor further comprises a first supportingelement for supporting the first circuit board. In one embodiment, theforce sensor further comprises a second supporting element forsupporting the third circuit board.

In one embodiment, the first metal plate is in parallel with the secondmetal plate; the second metal plate is in parallel with the third metalplate; the fourth metal plate is in parallel with the second metalplate; the fifth metal plate is in parallel with the second metal plate.Alternatively, the distance between the first and the second metal plateequals to the distance between the second metal plate and the thirdmetal plate. The distance between the fourth and the second metal plateequals to the distance between the second metal plate and the fifthmetal plate.

In one embodiment, the first metal plate is on top of the fourth metalplate. Alternatively, the third metal plate is on top of the fifth metalplate.

In one embodiment, area of the first metal plate equals to area of thefourth metal plate. Alternatively, area of the third metal plate equalsto area of the fifth metal plate.

In one embodiment, a first capacitor is formed by the first and thesecond metal plates; a second capacitor is formed by the second and thethird metal plates; a third capacitor is formed by the fourth and thesecond metal plates; a fourth capacitor is formed by the second and thefifth metal plates. Alternatively, the impedance of the first capacitorequals to the impedance of the second capacitor if the first circuitboard is not bending. Alternatively, the impedance of the thirdcapacitor equals to the impedance of the fourth capacitor if the thirdcircuit board is not bending. Alternatively, the impedance of the firstcapacitor equals to the impedance of the third capacitor, the impedanceof the second capacitor equals to the impedance of the fourth capacitor.

In one embodiment, the first, the second, and the third circuit boardsare all printed circuit boards.

One aspect of the application is to provide a force sensor, comprises afirst circuit board containing a first metal plate for receiving signalwith a first frequency group; a second circuit board in parallel withthe first circuit board containing a second metal plate, a third metalplate, a fourth metal plate and a fifth metal plate which are intact andparallel to each other, wherein the third metal plate and the fourthmetal plate for receiving signal with a second frequency group, whereinthe second metal plate is coupled to the fifth metal plate foroutputting an electric signal; a third circuit board containing a sixthmetal plate for receiving signal with the first frequency board, whereinthe second circuit board is placed in between the first and the thirdcircuit boards; and a ramp means for bending the first circuit boardupward and bending the third circuit board downward.

In one embodiment, the force sensor further comprises a first supportingelement for supporting the first circuit board. In one embodiment, theforce sensor further comprises a second supporting element forsupporting the third circuit board.

In one embodiment, the first metal plate is in parallel with the secondmetal plate; the second metal plate is in parallel with the third metalplate; the third metal plate is in parallel with the fourth metal plate;the fourth metal plate is in parallel with the fifth metal plate; andthe fifth metal plate is in parallel with the six metal plate.Alternatively, the distance between the first and the second metal plateequals to the distance between the second metal plate and the thirdmetal plate. The distance between the fourth and the fifth metal plateequals to the distance between the fifth metal plate and the sixth metalplate.

In one embodiment, the first metal plate is on top of the sixth metalplate.

In one embodiment, area of the first metal plate equals to area of thesixth metal plate. Alternatively, area of the second metal plate is ontop of the fifth metal plate. Alternatively, area of the third metalplate is on top of the fourth metal plate.

In one embodiment, a first capacitor is formed by the first and thesecond metal plates; a second capacitor is formed by the second and thethird metal plates; a third capacitor is formed by the fourth and thefifth metal plates; a fourth capacitor is formed by the fifth and thesixth metal plates. Alternatively, the impedance of the first capacitorequals to the impedance of the second capacitor if the first circuitboard is not bending. Alternatively, the impedance of the thirdcapacitor equals to the impedance of the fourth capacitor if the thirdcircuit board is not bending. Alternatively, the impedance of the firstcapacitor equals to the impedance of the fourth capacitor, the impedanceof the second capacitor equals to the impedance of the third capacitor.

In one embodiment, the first, the second, and the third circuit boardsare all printed circuit boards.

One aspect of the application is to provide a force sensor, comprises: afirst metal plate, a second metal plate, and third metal plate which areintact and sequentially parallel to each other, wherein the first metalplate for receiving signal with a first frequency group, the third metalplate for receiving signal with a second frequency group, the secondmetal plate for outputting an electric signal, wherein one end of thesecond metal plate is bendable.

One aspect of the application is to provide a force sensor, comprises: afirst metal plate, a second metal plate, and third metal plate which areintact and sequentially parallel to each other, wherein the first metalplate for outputting signal with a first current value, the third metalplate for outputting signal with a second current value, and the secondmetal plate for receiving a signal source, wherein one end of the secondmetal plate is bendable.

In one embodiment, the distance between the first metal plate and thesecond metal plate equals to the distance between the second metal plateand the third metal plate.

In one embodiment, a first capacitor is formed by the first and thesecond metal plates; a second capacitor is formed by the second and thethird metal plates. Alternatively, the impedance of the first capacitorequals to the impedance of the second capacitor if the first circuitboard is not bending.

One aspect of the application is to provide a force sensor, comprises: afirst metal plate, a second metal plate, and third metal plate which areintact and sequentially parallel to each other, wherein the first metalplate for outputting an electric signal, the second metal plate forreceiving signal with a first frequency group, the third metal plate forreceiving signal with a second frequency group, wherein one end of thefirst metal plate is bendable.

One aspect of the application is to provide a force sensor, comprises: afirst metal plate, a second metal plate, and third metal plate which areintact and sequentially parallel to each other, wherein the first metalplate for receiving a signal source, the second metal plate foroutputting signal with a first current value, the third metal plate foroutputting signal with a second current value, wherein one end of thefirst metal plate is bendable.

In one embodiment, the distance between the first metal plate and thesecond metal plate equals to the distance between the second metal plateand the third metal plate.

In one embodiment, a first capacitor is formed by the first and thesecond metal plates; a second capacitor is formed by the second and thethird metal plates. Alternatively, the impedance of the first capacitorequals to the impedance of the second capacitor if the first circuitboard is not bending.

One aspect of the application is to provide a transmitter, comprises amoving part for moving a stroke along an axis of the transmitter; andielectric material placing in the rear of the moving part; and aconductor placing in the rear of the dielectric material, wherein aforce sensitive capacitor is formed by the moving part, the dielectric,and the conductor.

In one embodiment, the transmitter further comprises a tip sectionplacing in the fore of the moving part. In one embodiment, the tipsection is a conductor coupling to the moving part. Alternatively, thetip section is configured to transmit an electric signal.

In one embodiment, the transmitter further comprises an elastic elementand a shell component, wherein the elastic element is configured toprovide elastic force between the moving part and the shell componentsuch that the moving part is pushed to the fore end of the stroke by theelastic force.

In one embodiment, the dielectric material is a dielectric film. Theconductor comprises a compressible conductor and a conductor base.Alternatively, the dielectric material is compressible dielectricmaterial.

In one embodiment, a contact surface of the dielectric material facingthe conductor comprises one of the following: a sloped surface, asurface with multiple bulges, a conical surface, and a surface withcentral bulge. Alternatively, a contact surface of the conductor facingthe dielectric material comprises one of the following: a slopedsurface, a surface with multiple bulges, a conical surface, and asurface with central bulge.

In one embodiment, the dielectric material and the conductor reside inan internal chamber of the shell component. Alternatively, the internalchamber is an empty cylinder.

In one embodiment, the moving part comprises a fore moving part and arear moving part. The fore moving part contacts with the tip section andelectrically couples to the tip section.

In one embodiment, the transmitter further comprises a circuit boardwhich connects to the conductor via a base wire and connects to themoving part via a moving part wire. Alternatively, the moving part wireis coupled to the elastic element.

In one embodiment, the elastic element does not surround the movingpart. Alternatively, the base wire does not surround the conductor.

One aspect of the application is to provide a circuit switch, comprises:a first circuit board, a second circuit board, a third circuit boardwhich are intact and sequentially parallel to each other, and a dualramp means, wherein a first end of the first circuit board and a firstend of the third circuit board contacts with the two ramps of the dualramp means, respectively, a first end of the second circuit board doesnot contact with the dual ramp means, the first end of the secondcircuit board comprises a circuit, a second point and a third point ofthe circuit contacts with and electrically couples to a first point ofthe first circuit board and a fourth point of the third circuit board,respectively.

In one embodiment, when the dual ramp means moves toward the secondcircuit board, the first circuit board and the third circuit boardpressed by the dual ramp means and bent upward and downward,respectively, whereby the electrically coupling between the first pointand the second point is open and the electrically coupling between thethird point and the fourth point is open, the voltage level of the firstconnection port is high.

In one embodiment, the first point is connected with a first connectionpoint and a high voltage in parallel, the fourth point is connected witha low voltage, the voltage level of the first connection point is low ifthe first point and the second point are shorted and the third point andthe fourth point are shorted, the voltage level of the first connectionpoint is high if the electrically coupling between the first point andthe second point is open or the electrically coupling between the thirdpoint and the fourth point is open.

In one embodiment, the dual ramp means connects with a tip section.

In one embodiment, the circuit is placed at the edge of the first end ofthe second circuit board.

One aspect of the application is to provide a circuit switch, comprises:a first circuit board, a second circuit board, a third circuit boardwhich are intact and sequentially parallel to each other, and a dualramp means, wherein a first end of the first circuit board and a firstend of the third circuit board contacts with the two ramps of the dualramp means, respectively, a first end of the second circuit board doesnot contact with the dual ramp means, the first end of the secondcircuit board comprises a circuit, a second point of the circuitcontacts with and electrically couples to a first point of the firstcircuit board.

In one embodiment, when the dual ramp means moves toward the secondcircuit board, the first circuit board and the third circuit boardpressed by the dual ramp means and bent upward and downward,respectively, whereby the electrically coupling between the first pointand the second point is open.

In one embodiment, the first point is connected with a first connectionpoint and a high voltage, the second point is connected with a lowvoltage, the voltage level of the first connection point is low if thefirst point and the second point are shorted, the voltage level of thefirst connection point is high if the electrically coupling between thefirst point and the second point is open.

In one embodiment, the dual ramp means connects with a tip section.

In one embodiment, the circuit is placed at the edge of the first end ofthe second circuit board.

One aspect of the application is to provide a stylus, comprises: acontrol unit, a tip section; and a circuit switch, which comprises: afirst circuit board, a second circuit board, a third circuit board whichare intact and sequentially parallel to each other, and a dual rampmeans, wherein a first end of the first circuit board and a first end ofthe third circuit board contacts with the two ramps of the dual rampmeans, respectively, a first end of the second circuit board does notcontact with the dual ramp means, the first end of the second circuitboard comprises a circuit, a second point and a third point of thecircuit contacts with and electrically couples to a first point of thefirst circuit board and a fourth point of the third circuit board,respectively, wherein the first point connects with a first connectionpoint of the control unit and a high voltage in parallel, the fourthpoint is connected with a low voltage, the voltage of the firstconnection port is low.

In one embodiment, when the dual ramp means moves toward the secondcircuit board, the first circuit board and the third circuit boardpressed by the dual ramp means and bent upward and downward,respectively, whereby the electrically coupling between the first pointand the second point is open and the electrically coupling between thethird point and the fourth point is open, the voltage level of the firstconnection port is high.

In one embodiment, the control unit is waked up if the voltage level ofthe first connection port turns high from low.

One aspect of the application is to provide a stylus, comprises: acontrol unit, a tip section; and a circuit switch, which comprises: afirst circuit board, a second circuit board, a third circuit board whichare intact and sequentially parallel to each other, and a dual rampmeans, wherein a first end of the first circuit board and a first end ofthe third circuit board contacts with the two ramps of the dual rampmeans, respectively, a first end of the second circuit board does notcontact with the dual ramp means, the first end of the second circuitboard comprises a circuit, a second point of the circuit contacts withand electrically couples to a first point of the first circuit board,wherein the first point connects with a first connection point of thecontrol unit and a high voltage in parallel, the second point isconnected with a low voltage, the voltage of the first connection portis low.

In one embodiment, when the dual ramp means moves toward the secondcircuit board, the first circuit board and the third circuit boardpressed by the dual ramp means and bent upward and downward,respectively, whereby the electrically coupling between the first pointand the second point is open, the voltage level of the first connectionport is high.

In one embodiment, the control unit is waked up if the voltage level ofthe first connection port turns high from low.

One aspect of the application is to provide a method for a transmitter,comprises: transmitting a first period electric signal during a firsttime period; and transmitting a second period electric signal during asecond time period, wherein frequency group contained in the firstperiod electric signal is different from frequency group contained inthe second period electric signal.

One aspect of the application is to provide a transmitter, which isconfigured for transmitting a first period electric signal during afirst time period; and transmitting a second period electric signalduring a second time period, wherein frequency group contained in thefirst period electric signal is different from frequency group containedin the second period electric signal.

One aspect of the application is to provide a touch sensitive system,comprises a transmitter, a touch panel and a touch sensitive processingapparatus coupled to the touch panel, which is configured for detectingthe transmitter according to a first period electric signal and a secondperiod electric signal. The transmitter is configured for transmittingthe first period electric signal during a first time period; andtransmitting the second period electric signal during a second timeperiod, wherein frequency group contained in the first period electricsignal is different from frequency group contained in the second periodelectric signal.

In one embodiment, the frequency group contains one or more frequencies.

In one embodiment, the first time period is after a beacon signaldetected by the transmitter. Alternatively, there exists a first delaytime between the beacon signal detection and the first time period.

In one embodiment, there exists a second delay time between the firsttime period and the second time period.

In one embodiment, there exists a third delay time after the second timeperiod.

In one embodiment, prior to the detection of the beacon signal, thetransmitter detects an interference signal. Alternatively, theinterference signal comprises signals which are coherent to the firstperiod electric signal and the second electric signal.

Please refer to the Table 1, in one embodiment, if a tip section of thetransmitter does not touch, a first signal source and a second signalsource of the transmitter simultaneously transmit signals with the samefrequency group.

Please refer to the Table 1, in one embodiment, if the tip section ofthe transmitter does not touch and a first switch of the transmitter isopen, the first signal source and the second signal sourcesimultaneously transmit signals with a first frequency group; if the tipsection does not touch and the first switch is shorted, the first signalsource and the second signal source simultaneously transmit signals witha second frequency group, the first frequency group is different to thesecond frequency group.

Please refer to the Table 1, in one embodiment, if the tip section ofthe transmitter does not touch and a second switch of the transmitter isopen, the first signal source and the second signal sourcesimultaneously transmit signals with the first frequency group; if thetip section does not touch and the first switch is shorted, the firstsignal source and the second signal source simultaneously transmitsignals with a third frequency group, the first frequency group isdifferent to the third frequency group.

Please refer to the Table 2, in one embodiment, if a tip section of thetransmitter does touch, a first signal source and a second signal sourceof the transmitter transmit signals with different frequency groupsduring the second time period and the first time period.

Please refer to the Table 2, in one embodiment, if the tip section ofthe transmitter does touch and a first switch of the transmitter isopen, the second signal source transmits signal with a first frequencygroup during the first time period; if a tip section of the transmitterdoes touch and the first switch of the transmitter is shorted, thesecond signal source transmits signal with a second frequency groupduring the first time period, the first frequency group is different tothe second frequency group.

Please refer to the Table 2, in one embodiment, if the tip section ofthe transmitter does touch and a second switch of the transmitter isopen, the first signal source transmits signal with a third frequencygroup during the second time period; if a tip section of the transmitterdoes touch and the second switch of the transmitter is shorted, thefirst signal source transmits signal with the second frequency groupduring the second time period, the third frequency group is different tothe second frequency group.

In one embodiment, a ratio of a first signal strength M1 transmitted bythe first signal source during the second time period and a secondsignal strength M2 transmitted by the second signal source during thefirst time period is corresponding to a pressure on the transmitter.

In one embodiment, a ring electrode transmits a zeroth period electricsignal during a zeroth time period, the zeroth time period is after thetransmitter detects the beacon signal. Alternatively, there exists azeroth delay time between the detection of the beacon signal and thezeroth time period.

In one embodiment, the ring electrode does not transmit electric signalduring the first time period and the second time period.

In one embodiment, frequency group contained in the zeroth periodelectric signal is different to frequency group contained the firstperiod electric signal and the second period electric signal.

One aspect of the application is to provide a method for a transmitter,comprises: transmitting a first period electric signal during a firsttime period; and transmitting a second period electric signal during asecond time period, wherein frequency group contained in the firstperiod electric signal is as the same as frequency group contained inthe second period electric signal.

One aspect of the application is to provide a transmitter, which isconfigured for transmitting a first period electric signal during afirst time period; and transmitting a second period electric signalduring a second time period, wherein frequency group contained in thefirst period electric signal is as the same as frequency group containedin the second period electric signal.

One aspect of the application is to provide a touch sensitive system,comprises a transmitter, a touch panel and a touch sensitive processingapparatus coupled to the touch panel, which is configured for detectingthe transmitter according to a first period electric signal and a secondperiod electric signal. The transmitter is configured for transmittingthe first period electric signal during a first time period; andtransmitting the second period electric signal during a second timeperiod, wherein frequency group contained in the first period electricsignal is as the same as frequency group contained in the second periodelectric signal.

In one embodiment, the frequency group contains one or more frequencies.

In one embodiment, the first time period is after a beacon signaldetected by the transmitter. Alternatively, there exists a first delaytime between the beacon signal detection and the first time period.

In one embodiment, there exists a second delay time between the firsttime period and the second time period.

In one embodiment, there exists a third delay time after the second timeperiod.

In one embodiment, prior to the detection of the beacon signal, thetransmitter detects an interference signal. Alternatively, theinterference signal comprises signals which are coherent to the firstperiod electric signal and the second electric signal.

Please refer to the Table 3, in one embodiment, if a tip section of thetransmitter does not touch, a first signal source and a second signalsource of the transmitter simultaneously transmit signals with the samefrequency group.

Please refer to the Table 3, in one embodiment, if the tip section ofthe transmitter does not touch and a first switch of the transmitter isopen, the first signal source and the second signal sourcesimultaneously transmit signals with a first frequency group; if the tipsection does not touch and the first switch is shorted, the first signalsource and the second signal source simultaneously transmit signals witha second frequency group, the first frequency group is different to thesecond frequency group.

Please refer to the Table 3, in one embodiment, if the tip section ofthe transmitter does not touch and a second switch of the transmitter isopen, the first signal source and the second signal sourcesimultaneously transmit signals with the first frequency group; if thetip section does not touch and the first switch is shorted, the firstsignal source and the second signal source simultaneously transmitsignals with a third frequency group, the first frequency group isdifferent to the third frequency group.

Please refer to the Table 4, in one embodiment, if a tip section of thetransmitter does touch, a first signal source and a second signal sourceof the transmitter transmit signals with the same frequency groupsduring the second time period and the first time period, respectively.

Please refer to the Table 4, in one embodiment, if a tip section of thetransmitter does touch and a first switch of the transmitter is open,the second signal source transmits signal with a first frequency groupduring the first time period; if a tip section of the transmitter doestouch and the first switch of the transmitter is shorted, the secondsignal source transmits signal with a second frequency group during thefirst time period, the first frequency group is different to the secondfrequency group.

Please refer to the Table 4, in one embodiment, if the tip section ofthe transmitter does touch and a second switch of the transmitter isopen, the first signal source transmits signal with a third frequencygroup during the second time period; if a tip section of the transmitterdoes touch and the second switch of the transmitter is shorted, thefirst signal source transmits signal with the second frequency groupduring the second time period, the third frequency group is different tothe second frequency group.

In one embodiment, a ring electrode transmits a zeroth period electricsignal during a zeroth time period, the zeroth time period is after thetransmitter detects the beacon signal. Alternatively, there exists azeroth delay time between the detection of the beacon signal and thezeroth time period.

In one embodiment, the ring electrode does not transmit electric signalduring the first time period and the second time period.

In one embodiment, frequency group contained in the zeroth periodelectric signal is different to frequency group contained the firstperiod electric signal and the second period electric signal.

In one embodiment, a ratio of a first signal strength M1 transmitted bythe first signal source during the second time period and a secondsignal strength M2 transmitted by the second signal source during thefirst time period is corresponding to a pressure on the transmitter.

One aspect of the application is to provide a method for detecting atransmitter, comprises: detecting a first period electric signal emittedfrom the transmitter during a first time period; and detecting a secondperiod electric signal emitted from the transmitter from a second timeperiod, wherein frequency group contained in the first period electricsignal is different from frequency group contained in the second periodelectric signal.

One aspect of the application is to provide a touch sensitive processingapparatus for detecting a transmitter, coupled to a touch panel whichcomprises a plurality of first electrodes and a plurality of secondelectrodes as well as multiple sensing points located where theintersections, the touch sensitive processing apparatus is configuredfor detecting a first period electric signal emitted from thetransmitter during a first time period; and detecting a second periodelectric signal emitted from the transmitter from a second time period,wherein frequency group contained in the first period electric signal isdifferent from frequency group contained in the second period electricsignal.

One aspect of the application is to provide a touch sensitive systemcomprises a transmitter, a touch panel, and a touch sensitive processingapparatus, coupled to the touch panel, configured for detecting a firstperiod electric signal emitted from the transmitter during a first timeperiod; and detecting a second period electric signal emitted from thetransmitter from a second time period, wherein frequency group containedin the first period electric signal is different from frequency groupcontained in the second period electric signal.

In one embodiment, the frequency group contains one or more frequencies.

In one embodiment, the first time period is after a beacon signaldetected by the transmitter. Alternatively, there exists a first delaytime between the beacon signal detection and the first time period.

In one embodiment, there exists a second delay time between the firsttime period and the second time period.

In one embodiment, there exists a third delay time after the second timeperiod.

In one embodiment, prior to the detection of the beacon signal, thetransmitter detects an interference signal. In one embodiment, aninterference signal is detected after the first time period. In oneembodiment, an interference signal is detected after the second timeperiod. Alternatively, the interference signal comprises signals whichare coherent to the first period electric signal and the second electricsignal.

Please refer to the Table 1, in one embodiment, if the transmittersimultaneously transmit signals with the same frequency group, it isdetermined that a tip section of the transmitter does not touch.

Please refer to the Table 1, in one embodiment, if the transmittertransmits signals with a first frequency group during a first timeperiod, it is determined that the tip section does not touch and a firstswitch of the transmitter is open; if the transmitter transmits signalswith a second frequency group during the first time period, it isdetermined that the tip section does not touch and the first switch ofthe transmitter is shorted, wherein the first frequency group isdifferent to the second frequency group.

Please refer to the Table 1, in one embodiment, if the transmittertransmits signals with a first frequency group during a second timeperiod, it is determined that the tip section does not touch and asecond switch of the transmitter is open; if the transmitter transmitssignals with a third frequency group during the second time period, itis determined that the tip section does not touch and the first switchof the transmitter is shorted, wherein the first frequency group isdifferent to the third frequency group.

Please refer to the Table 2, in one embodiment, if the transmittertransmits signals with different frequency groups during the first timeperiod and the second time period, it is determined that a tip sectionof the transmitter does touch.

Please refer to the Table 2, in one embodiment, if the transmittertransmits signal with a first frequency group during the first timeperiod, it is determined that the tip section does touch and a firstswitch of the transmitter is open; if the transmitter transmits signalwith a second frequency group during the first time period, it isdetermined that the tip section does touch and the first switch of thetransmitter is shorted, wherein the first frequency group is differentto the third frequency group.

Please refer to the Table 2, in one embodiment, if the transmittertransmits signal with a third frequency group during the second timeperiod, it is determined that the tip section does touch and a secondswitch of the transmitter is open; if the transmitter transmits signalwith a second frequency group during the second time period, it isdetermined that the tip section does touch and the second switch of thetransmitter is shorted, wherein the first frequency group is differentto the third frequency group.

In one embodiment, a ratio of a first signal strength M1 transmitted bythe first signal source during the second time period and a secondsignal strength M2 transmitted by the second signal source during thefirst time period is calculated; and a pressure on the transmitteraccording to the ratio is calculated.

In one embodiment, detecting a zeroth period electric signal transmittedby the transmitter during a zeroth time period, the zeroth time periodis after the transmitter detects the beacon signal. Alternatively, thereexists a zeroth delay time between the detection of the beacon signaland the zeroth time period.

In one embodiment, frequency group contained in the zeroth periodelectric signal is different to frequency group contained the firstperiod electric signal and the second period electric signal.

One aspect of the application is to provide a method for detecting atransmitter, comprises: detecting a first period electric signal emittedfrom the transmitter during a first time period; and detecting a secondperiod electric signal emitted from the transmitter from a second timeperiod, wherein frequency group contained in the first period electricsignal is as the same as frequency group contained in the second periodelectric signal.

One aspect of the application is to provide a touch sensitive processingapparatus for detecting a transmitter, coupled to a touch panel whichcomprises a plurality of first electrodes and a plurality of secondelectrodes as well as multiple sensing points located where theintersections, the touch sensitive processing apparatus is configuredfor detecting a first period electric signal emitted from thetransmitter during a first time period; and detecting a second periodelectric signal emitted from the transmitter from a second time period,wherein frequency group contained in the first period electric signal isas the same as frequency group contained in the second period electricsignal.

One aspect of the application is to provide a touch sensitive systemcomprises a transmitter, a touch panel, and a touch sensitive processingapparatus, coupled to the touch panel, configured for detecting a firstperiod electric signal emitted from the transmitter during a first timeperiod; and detecting a second period electric signal emitted from thetransmitter from a second time period, wherein frequency group containedin the first period electric signal is as the same as frequency groupcontained in the second period electric signal.

In one embodiment, the frequency group contains one or more frequencies.

In one embodiment, the first time period is after a beacon signaldetected by the transmitter. Alternatively, there exists a first delaytime between the beacon signal detection and the first time period.

In one embodiment, there exists a second delay time between the firsttime period and the second time period.

In one embodiment, there exists a third delay time after the second timeperiod.

In one embodiment, prior to the detection of the beacon signal, thetransmitter detects an interference signal. In one embodiment, aninterference signal is detected after the first time period. In oneembodiment, an interference signal is detected after the second timeperiod. Alternatively, the interference signal comprises signals whichare coherent to the first period electric signal and the second electricsignal.

Please refer to the Table 3, in one embodiment, if the first periodelectric signals with the same frequency group and the second periodelectric signals with the same frequency group, it is determined that atip section of the transmitter does not touch.

Please refer to the Table 3, in one embodiment, if the transmittertransmits signals with a first frequency group, it is determined thatthe tip section does not touch and a first switch of the transmitter isopen; if the transmitter transmits signals with a second frequencygroup, it is determined that the tip section does not touch and thefirst switch of the transmitter is shorted, wherein the first frequencygroup is different to the second frequency group.

Please refer to the Table 3, in one embodiment, if the transmittertransmits signals with a first frequency group, it is determined thatthe tip section does not touch and a second switch of the transmitter isopen; if the transmitter transmits signals with a third frequency group,it is determined that the tip section does not touch and the firstswitch of the transmitter is shorted, wherein the first frequency groupis different to the third frequency group.

Please refer to the Table 4, in one embodiment, if the first periodelectric signals with the same frequency group and the second periodelectric signals with the same frequency group and a ratio of a signalstrength M1 of the first period electric signal and a signal strength M2of the second period electric signal does not fall into a first range,it is determined that a tip section of the transmitter does not touch.

Please refer to the Table 4, in one embodiment, if the transmittertransmits signal with a first frequency group during the first timeperiod and the ratio does not fall into a first range, it is determinedthat the tip section does touch and a first switch of the transmitter isopen; if the transmitter transmits signal with a second frequency groupduring the first time period and the ratio does not fall into the firstrange, it is determined that the tip section does touch and the firstswitch of the transmitter is shorted, wherein the first frequency groupis different to the third frequency group.

Please refer to the Table 4, in one embodiment, if the transmittertransmits signal with a third frequency group during the second timeperiod and the ratio does not fall into a first range, it is determinedthat the tip section does touch and a first switch of the transmitter isopen; if the transmitter transmits signal with a second frequency groupduring the second time period and the ratio does not fall into the firstrange, it is determined that the tip section does touch and the secondswitch of the transmitter is shorted, wherein the first frequency groupis different to the third frequency group.

In one embodiment, a ratio of a first signal strength M1 transmitted bythe first signal source during the second time period and a secondsignal strength M2 transmitted by the second signal source during thefirst time period is calculated; and a pressure on the transmitteraccording to the ratio is calculated.

In one embodiment, detecting a zeroth period electric signal transmittedby the transmitter during a zeroth time period, the zeroth time periodis after the transmitter detects the beacon signal. Alternatively, thereexists a zeroth delay time between the detection of the beacon signaland the zeroth time period.

In one embodiment, frequency group contained in the zeroth periodelectric signal is as the same as frequency group contained the firstperiod electric signal and the second period electric signal.

One aspect of the present application is to provide a transmitter,comprises: a tip section and a ring electrode surrounding the tipsection, wherein the tip section is not electric coupling to the ringelectrode.

In one embodiment, the ring electrode comprises multiple disconnectedelectrodes.

In one embodiment, the transmitter transmits electric signals via thering electrode and the tip section during a zeroth time period. Inanother embodiment, the transmitter transmits electric signals via thetip section during a first time period. Alternatively, the first timeperiod is after the zeroth time period.

In one embodiment, electric signals emitted from the ring electrode andthe tip section contains the same frequency group. Alternatively,electric signal emitted from the ring electrode contains frequency groupdifferent to the frequency group contained in the electric signalemitted from the tip electrode.

One aspect of the present application is to provide a method fordetecting a position of a transmitter, wherein the transmitter comprisesa tip section and a ring electrode surrounding the tip section, whereinthe tip section is not electric coupling to the ring electrode, themethod comprises detecting electric signals emitted from the ringelectrode and the tip section during a zeroth time period; and detectingelectric signals emitted from the tip section during a first timeperiod.

One aspect of the present application is to provide a touch sensitiveprocessing apparatus for detecting a position of a transmitter, whereinthe transmitter comprises a tip section and a ring electrode surroundingthe tip section, wherein the tip section is not electric coupling to thering electrode, the touch sensitive processing apparatus is coupled to atouch panel which comprises a plurality of first electrodes and aplurality of second electrodes and multiple sensing points located wherethe intersections, the touch sensitive processing apparatus isconfigured for detecting electric signals emitted from the ringelectrode and the tip section during a zeroth time period; and detectingelectric signals emitted from the tip section during a first timeperiod.

One aspect of the present application is to provide a touch sensitivesystem, comprises a transmitter, a touch panel, and a touch sensitiveprocessing apparatus coupled to the touch panel. The transmittercomprises a tip section and a ring electrode surrounding the tipsection, wherein the tip section is not electric coupling to the ringelectrode. The touch sensitive processing apparatus is coupled to atouch panel which comprises a plurality of first electrodes and aplurality of second electrodes and multiple sensing points located wherethe intersections, the touch sensitive processing apparatus isconfigured for detecting electric signals emitted from the ringelectrode and the tip section during a zeroth time period; and detectingelectric signals emitted from the tip section during a first timeperiod.

In one embodiment, electric signal emitted from the ring electrode andthe tip section contains the same frequency group. Alternatively,electric signal emitted from the ring electrode contains frequency groupdifferent to the frequency group contained in the electric signalemitted from the tip electrode.

In one embodiment, the method further comprises calculating a firstcentroid position of the transmitter according to the electric signaldetected during the zeroth time period. Alternatively, the methodfurther comprises calculating a second centroid position of thetransmitter according to the electric signal detected during the firsttime period.

In one embodiment, the method further comprises calculating a surfaceposition where the transmitter touches the touch panel according to thefirst centroid position and the second centroid position, wherein thesurface position is the position where the axis of the tip sectionprojecting to a surface layer of the touch panel.

In one embodiment, the method further comprises calculating a displayposition where the transmitter touches the touch panel according to thefirst centroid position and the second centroid position, wherein thedisplay position is the position where the axis of the tip sectionprojecting to a display layer of the touch panel.

In one embodiment, the method further comprises calculating aninclination angle of the transmitter touches the touch panel accordingto the first centroid position and the second centroid position.

One aspect of the present application is to provide a method forcalculating a surface position where a transmitter touches a touchpanel, the method comprises: receiving a first centroid position of thetransmitter, wherein the first centroid is calculated according toelectric signals emitted from a ring electrode and a tip section of thetransmitter, receiving a second centroid position of the transmitter,wherein the first centroid is calculated according to electric signalsemitted from the a tip section of the transmitter; and calculating thesurface position where the transmitter touches the touch panel accordingto the first centroid position and the second centroid position, whereinthe surface position is the position where the axis of the tip sectionprojecting to a surface layer of the touch panel.

One aspect of the present application is to provide a method forcalculating a display position where a transmitter touches a touchpanel, the method comprises: receiving a first centroid position of thetransmitter, wherein the first centroid position is calculated accordingto electric signals emitted from a ring electrode and a tip section ofthe transmitter, receiving a second centroid position of thetransmitter, wherein the second centroid position is calculatedaccording to electric signals emitted from the a tip section of thetransmitter; and calculating the display position where the transmittertouches the touch panel according to the first centroid position and thesecond centroid position, wherein the display position is the positionwhere the axis of the tip section projecting to a display layer of thetouch panel.

One aspect of the present application is to provide a method forcalculating an inclination angle of a transmitter touches a touch panel,the method comprises: receiving a first centroid position of thetransmitter, wherein the first centroid position is calculated accordingto electric signals emitted from a ring electrode and a tip section ofthe transmitter, receiving a second centroid position of thetransmitter, wherein the second centroid position is calculatedaccording to electric signals emitted from the a tip section of thetransmitter; and calculating the inclination angle according to thefirst centroid position and the second centroid position.

In one embodiment, the first centroid position is calculated during azeroth time period. In one embodiment, the second centroid position iscalculated during a first time period. Alternatively, the first timeperiod is after the zeroth time period. In one embodiment, electricsignal emitted from the ring electrode contains frequency groupdifferent to the frequency group contained in the electric signalemitted from the tip electrode.

One aspect of the present application is to provide a display method,comprises: receiving a position of a transmitter; receiving aninclination angle of the transmitter; determining a display areaaccording to the position and the inclination angle.

In one embodiment, the position is one of the followings: a firstcentroid position, a second centroid position, a surface position; and adisplay position. The first centroid position is calculated according toelectric signals emitted from a ring electrode and a tip section of thetransmitter. The second centroid position is calculated according toelectric signals emitted from the tip section of the transmitter. Thesurface position is the position where the axis of the tip sectionprojecting to a surface layer of the touch panel. The display positionis the position where the axis of the tip section projecting to adisplay layer of the touch panel. In one embodiment, electric signalemitted from the ring electrode contains frequency group different tothe frequency group contained in the electric signal emitted from thetip electrode.

In one embodiment, the display area comprises an ellipse. Alternatively,the position is located one of the followings: a center of the ellipse,one of two focal points of the ellipse; and one of intersections of thesemi-major axis and the ellipse. In one embodiment, the semi-major axisis corresponding to the direction of the inclination angle.

In one embodiment, the display area comprises a tear drop shape.Alternatively, the position is located one of the followings: a centerof the tear drop shape, a top of the tear drop shape; and an end of thetear drop shape. In one embodiment, the direction of the tear drop shapeis corresponding to the direction of the inclination angle.

In one embodiment, the direction of the display area is corresponding tothe direction of the inclination angle. Alternatively, the size of thedisplay area is corresponding to the inclination angle. Alternatively,the color of the display area is corresponding to one of the followings:the inclination angle; and the direction of the inclination angle.

In one embodiment, it further comprises receiving a pressure of thetransmitter; the size of the display area is corresponding to thepressure.

One aspect of the present application is to provide a method forcontrolling the transmitter, comprises: transmitting a first electricsignal with a first signal strength if a force sensor of the transmitterdoes not sense any force; transmitting a second electric signal with asecond signal strength if the force sensor does sense force, wherein thefirst signal strength is larger than the second signal strength.

In one embodiment, the force sensor comprises a tip section of thetransmitter.

In one embodiment, the transmitter further comprises a ring electrode.The first electric signal is transmitted via the tip section and thering electrode, the second electric signal is transmitted via the tipsection.

One aspect of the application is to provide a transmitter, comprises aforce sensor and a control unit, which is configured to transmitting afirst electric signal with a first signal strength if a force sensor ofthe transmitter does not sense any force; transmitting a second electricsignal with a second signal strength if the force sensor does senseforce, wherein the first signal strength is larger than the secondsignal strength.

Code Division Multiple Access (CDMA) is a wireless spread spectrumtelecommunication technology adopted in the third generation of mobiletelecommunication service. In wireless telecommunication techniques,spread spectrum means the bandwidth consumed by the carrier signalitself exceeds the bandwidth of the contents carried by the carriersignal. Using a carrier signal with bigger bandwidth allows for bettertolerance to interfering noise signals during transmission. DirectSequence Spread Spectrum (DSSS) is one of spread spectrum techniques.DSSS modulation technique employs a bit sequence code called a pseudonoise (PN). The bit sequence code or PN code includes pulse waves eachwith a short period, which period may be called a chip. The period of achip is shorter than that of a data or signal code (thereinafter datacode). In other words, the bandwidth consumed by a PN code is largerthan that consumed by a data code. Therefore, modulating a data code ofa smaller bandwidth into a PN code of a larger bandwidth means thebandwidth of the carrier signal after modulation matches or is similarto that of the PN code.

During the process of modulation with a carrier signal, a main step isto multiply a data code and a PN code, which PN code is usually a pseudorandom sequence usually including a combination of 1 and −1. Onecharacteristic of PN code is that multiplying a sequence of PN code bythe same PN code returns the same PN code, because 1×1=1 and −1×−1=1.This multiplication with the same PN code is called despreading.Accordingly, when the receiving end also knows the sequence of PN codeused in the modulation process, it can perform a process of despreadingto obtain the data or content code carried by the carrier signal.

Referring to FIG. 30, some waveforms of a spread spectrum technique areillustrated. The waveform on the top portion of FIG. 30 is a data code,the waveform on the middle portion of FIG. 30 is a pseudo randomsequence or a so-called PN code, and the waveform on the bottom portionof FIG. 30 is a carrier signal. According to FIG. 30 it can be knownthat when the electric potential of the data code is high, the waveformsof the carrier signal and the PN code are opposite to each other. Whenthe electric potential of the data code is low, the waveforms of thecarrier signal and the PN code are the same. In other words, thereceiving end can compare the waveforms of the carrier signal and the PNcode, and when the two waveforms are opposite to each other, thereceiving end can infer that the electric potential of the data code ishigh at this time. Conversely, when the waveforms of the carrier signaland the PN code are the same, the receiving end can infer that theelectric potential of the data code is low at this time. Accordingly,the receiving end can infer the state of the electric potential of thedata code as long as the PN code used is known.

Referring to FIG. 31, which shows a variant of the embodiment as shownin FIG. 1. The touch sensitive system 100 further includes a firststylus 111 and/or a second stylus 112. In one embodiment, these styli111 and 112 are active.

In some embodiments, the active stylus 111 or 112 may be commanded tocode the sensing values from each sensor thereon to the data codesmentioned above. The so-called sensing value of a sensor may include butnot limited to the following: a pressure value on a tip section ofstylus; sensing value presenting whether a button being pressed or not;sensing value of attitude of a gyroscope; sensing value of accelerationof an accelerometer; sensing value of battery power; serial number ofstylus; and wireless signal intensity received by stylus. Then, theactive stylus 111 or 112 codes the data code(s) mentioned above tocarrier signal(s) by the process of spread spectrum according to certaina PN code. After that, the active stylus 111 or 112 emits the electricalsignals including the carrier signals by the tip section thereof. Afterreceiving the electrical signals, the touch sensitive processingapparatus of the touch sensitive screen at least obtains the followingmessage: the proximate position of the active stylus 111 or 112 on thetouch sensitive screen; the PN code form used by the active stylus 111or 112, as well as the content of the aforementioned data code.

In the above-described process, the touch sensitive processing apparatus130 at the receiving end must synchronize or align the received carriersignal and PN code, in order to obtain the correct (state of the) datacode. However, when the active stylus 111 or 112 emits electricalsignal, the touch sensitive processing apparatus 130 can not necessarilyimmediately synchronize the received carrier signal and PN code, whichresults in difficulties in obtaining/inferring the data code.

The receiving end can usually postpone the multiplication of a receivedknown carrier signal or a local oscillator (LO) signal produced by thereceiving end, and a known PN code, for a period of time, and thenperform the multiplication, which postponing of multiplication may becalled a correlation. When two signals are not synchronous, thecalculated value of their correlation will not exceed a threshold value.Conversely, when the two signals are synchronous, the calculated valueof their correlation will exceed the threshold value. And when the twosignals are not synchronous, the receiving end can repetitively adjustthe postponing period until the two signals are synchronous or aligned.

In one embodiment of the present invention, electrical signal or thecarrier signal emitted by the active stylus may comprise a signal frameincluding a preamble code followed by a data code section. The data codesection may be used for transmitting a sensing state of a sensor on thestylus. For example, sensing values e.g. resulting from sensing whethera button on the stylus has been pressed down, or associated with thepressure value sensed by the tip section of the stylus, can betransmitted.

In a variant of this embodiment, the active stylus 111 or 112 can emit acomplete signal frame described above at intervals, to inform of thestate of the sensor thereof. In another variant of this embodiment,different active styluses may have different preamble codes and/or PNcodes, enabling the touch sensitive processing apparatus 130 to identifyand/or distinguish at least two active styluses simultaneouslyapproaching or touching the touch sensitive screen 120. For example, thefirst active stylus 111 emits a first preamble code modulated by a firstPN code, the second active stylus 112 emits a second preamble codemodulated by a second PN code. And then, the touch sensitive processingapparatus 130 demodulates or performs despreading to the received signalby the first PN code and the second PN code respectively, it candetermine the first preamble code and/or the second preamble code havingbeen received.

When the touch sensitive processing apparatus 130 knows the electricalsignal having two preamble codes, it can determine the first activestylus 111 and the second active stylus 112 approximate the touchsensitive screen 120 according to the first PN code and the second PNcode which are correspondingly associated to the first active stylus 111and the second active stylus 112. Since the touch sensitive processingapparatus 130 knows the timing of the first PN code and the second PNcode, it can make the first and the second PN codes respectivelysynchronize the signal frames emitted by the first active stylus 111 andthe second active stylus 112, and then decodes the data code sectionbehind the signal frame.

In one embodiment of the present invention, in order to reach thesynchronous state soon, some or all of the second electrodes 122 areconnected to the same line or channel, called synchronization line orsynchronization channel, and the touch sensitive processing apparatus isresponsible for detecting on the synchronization line or synchronizationchannel and performing synchronization with respect to the knownpreamble code.

Persons having ordinary skill in the art can appreciate that when thetouch sensitive processing apparatus 130 has known the PN code and theintendedly transmitted preamble code, the touch sensitive processingapparatus 130 can synchronize with the carrier signal by using wellknown technique(s), or find the phase shift between the carrier signaland the local oscillator signal. When ascertaining the phase shiftbetween the two signals, any of the first electrodes 121 receiving theelectrical signal is caused to decode the following data code section,in order to obtain the sensor state transmitted by the active stylus 111or 112.

In one embodiment of the present invention, the aforementioned decodingstep may be performed to decode the following data code section withrespect to the carrier signal received by one of the first electrodes121, wherein the received carrier signal used for decoding has thelargest signal amount among all carrier signals received by all thefirst electrodes 121 and/or second electrodes 122.

In another embodiment of the present invention, the aforementioneddecoding step may be performed to decode the following data code sectionwith respect to the carrier signals received by some of the firstelectrodes 121, to obtain data codes which should match or be similar toeach other. If the data codes obtained do not match, the data codesobtained for the most instances may be regarded as the right one.

In addition, among the carrier signals received by the multiple firstelectrodes 121, after adjustment using the phase shift, the carriersignal that is the most correlated with the local oscillator signalshould have the smallest noise and is usually received by one of thefirst electrodes 121 that is closest to the active stylus 111 or 112.Accordingly, the position of the active stylus 111 or 112 relative toeach of the first electrodes 121 may be calculated based on deviationsof multiple instances of correlation involving the carrier signalreceived by each first electrode 121 and adjusted by using the phaseshift mentioned above. In other words, the coordinate(s) of the positionof the active stylus 111 on the second axis can be calculated as well.

Referring to FIG. 32, a flowchart of despreading method 3200 accordingto an embodiment of the present invention is illustrated. The touchsensitive processing apparatus 130 shown in FIG. 31 could perform thesteps of the flowchart shown in FIG. 32, whatever by software, hardware,or the combination of software and hardware. It should be noted that thestep numbers in FIG. 32 do not affect the steps performed in orderexcept that there is a causal relationship between the steps. Moreover,other steps which do not relate to the present invention may be insertedbetween the steps as well.

At step 3210, coupling at least two of the second electrodes as asynchronization channel. The touch sensitive processing apparatus 130may use analog switch or digital adder to implement this step. In avariant, the synchronization channel couples all of the secondelectrodes.

At step 3220, despreading a first preamble code of a first signal frameof received signal from the synchronization channel to retrieve a firstsynchronization information according to a first pseudo noise code.

At step 3230, decoding first data codes behind the first preamble codeof received signal from at least one of the first electrodes inaccordance with the first synchronization information and the firstpseudo noise code.

In a variation, an electrical signal used for decoding the first datacodes is from one of the multiple first electrodes which receive alargest electrical signal amount or a strongest electrical signal. Inanother variation, an electrical signal used for decoding the first datacodes is from some of the multiple first electrodes. In still anothervariation, the despreading method further includes: calculating multipledeviations of signal correlations of the multiple first electrodesaccording to the first synchronization information; and calculating aposition of the first active stylus on the second axis according to themultiple deviations.

At step 3240, despreading a second preamble code of a second signalframe of received signal from the synchronization channel to retrieve asecond synchronization information according to a second pseudo noisecode.

At step 3250, decoding second data codes behind the second preamble codeof received signal from at least one of the first electrodes inaccordance with the second synchronization information and the secondpseudo noise code.

In a variation, an electrical signal used for decoding the second datacodes is from one of the multiple first electrodes which receives alargest electrical signal amount or a strongest electrical signal. Inanother variation, an electrical signal used for decoding the seconddata codes is from some of the multiple first electrodes. In stillanother variation, the despreading method further includes: calculatingmultiple deviations of signal correlations of the multiple firstelectrodes according to the second synchronization information; andcalculating a position of the second active stylus on the second axisaccording to the multiple deviations.

One of the advantages of this invention is that the touch sensitiveprocessing apparatus 130 can rapidly synchronize the electrical signalsmodulated by DSSS in one signal frame and then decode the data codesection emitted by the active stylus/styli 111 and/or 112. Anotheradvantage of this invention is that when several active styli, such as111 and 112, operate at the same time, all of them are allowed to emitelectrical signals simultaneously. For example, as long as they usedifferent pseudo noise codes, even if they emit electrical signalssimultaneously, the touch sensitive processing apparatus 130 is stillable to distinguish the signal frames and data codes emitted from themin the received signals.

In an embodiment, this invention provides a despreading method beingapplicable to a touch sensitive screen which includes multiple firstelectrodes being parallel to a first axis and multiple second electrodesbeing parallel to a second axis. The despreading method includes thefollowing steps: coupling at least two of the second electrodes as asynchronization channel; despreading a first preamble code of a firstsignal frame of received signal from the synchronization channel toretrieve a first synchronization information according to a first pseudonoise code; and decoding a first data codes behind the first preamblecode of received signal from at least one of the first electrodes inaccordance with the first synchronization information and the firstpseudo noise code.

In certain embodiments, the first signal frame is from a first activestylus approaching the touch sensitive screen, the first data codesinclude at least one type of following information: a pressure on a tipsection of stylus; sensing value presenting whether a button beingpressed or not; sensing value of attitude of a gyroscope; sensing valueof acceleration of an accelerometer; sensing value of battery power;serial number of stylus; and wireless signal intensity received bystylus.

In certain embodiments, the synchronization channel couples all of themultiple second electrodes.

In certain embodiments, an electrical signal used for decoding the firstdata codes is from one of the multiple first electrodes which receives alargest electrical signal amount or a strongest electrical signal.

In certain embodiments, an electrical signal used for decoding the firstdata codes is from some of the multiple first electrodes. Thedespreading method further includes the following steps: calculatingmultiple deviations of signal correlations of the multiple firstelectrodes according to the first synchronization information; andcalculating a position of the first active stylus (emitting the firstsignal frame) on the second axis according to the multiple deviations.

In certain embodiments, the despreading method further includes thefollowing steps: despreading a second preamble code of a second signalframe of received signal from the synchronization channel to retrieve asecond synchronization information according to a second pseudo noisecode; and decoding a second data codes behind the second preamble codeof received signal from at least one of the multiple first electrodes inaccordance with the second synchronization information and the secondpseudo noise code, wherein the second signal frame is from a secondactive stylus approaching the touch sensitive screen.

In certain embodiments, the first signal frame and the second signalframe have at least some parts concurrently appearing in the signalreceived by the multiple first electrodes.

In an embodiment, this invention provides a touch sensitive system fordespreading. The touch sensitive system includes a touch sensitivescreen including multiple first electrodes being parallel to a firstaxis and multiple second electrodes being parallel to a second axis, anda touch sensitive processing apparatus connected to the multiple firstelectrodes and the multiple second electrodes. The touch sensitiveprocessing apparatus is configured to perform the following stepsincluding: coupling at least two of the multiple second electrodes as asynchronization channel; despreading a first preamble code of a firstsignal frame of received signal from the synchronization channel toretrieve a first synchronization information according to a first pseudonoise code; and decoding a first data codes behind the first preamblecode of received signal from at least one of the multiple firstelectrodes in accordance with the first synchronization information andthe first pseudo noise code.

In an embodiment, this invention provides a touch sensitive processingapparatus for despreading. The touch sensitive processing apparatus isconnected to multiple first electrodes on a touch sensitive screen whichare parallel to a first axis and multiple second electrodes on the touchsensitive screen which are parallel to a second axis. The touchsensitive processing apparatus is configured to perform the followingsteps including: coupling at least two of the multiple second electrodesas a synchronization channel; despreading a first preamble code of afirst signal frame of received signal from the synchronization channelto retrieve a first synchronization information according to a firstpseudo noise code; and decoding a first data codes behind the firstpreamble code of received signal from at least one of the multiple firstelectrodes in accordance with the first synchronization information andthe first pseudo noise code.

In certain embodiments, the first signal frame is from a first activestylus approaching the touch sensitive screen, the first data codesinclude at least one type of following information: a pressure on a tipsection of stylus; sensing value presenting whether a button beingpressed or not; sensing value of attitude of a gyroscope; sensing valueof acceleration of an accelerometer; sensing value of battery power;serial number of stylus; and wireless signal intensity received bystylus.

In certain embodiments, the synchronization channel couples all of themultiple second electrodes.

In certain embodiments, an electrical signal used for decoding the firstdata codes is from one of the multiple first electrodes which receives alargest electrical signal amount.

In certain embodiments, an electrical signal used for decoding the firstdata codes is from some of the multiple first electrodes. The touchsensitive processing apparatus is configured to further perform thefollowing steps including: calculating multiple deviations of signalcorrelations of the multiple first electrodes according to the firstsynchronization information; and calculating a position of the firstactive stylus (emitting the first signal frame) on the second axisaccording to the multiple deviations.

In certain embodiments, the touch sensitive processing apparatus isconfigured to further perform the following steps including: despreadinga second preamble code of a second signal frame of received signal fromthe synchronization channel to retrieve a second synchronizationinformation according to a second pseudo noise code; and decoding asecond data codes behind the second preamble code of received signalfrom at least one of the multiple first electrodes in accordance withthe second synchronization information and the second pseudo noise code,wherein the second signal frame is from a second active stylusapproaching the touch sensitive screen.

In certain embodiments, the first signal frame and the second signalframe have at least some parts concurrently appearing in the signalreceived by the multiple first electrodes.

Please refer to FIG. 33, which depicts a diagram of an embodiment of anactive stylus 111 in accordance with the present invention. The activestylus 111 may comprise a controller 3310, a clock signal module 3320, abattery 3330, the first component 221 with a first impedance Z1, thesecond component 222 with a second impedance Z2, and a tip section 230.The controller 3310 is configured for simultaneously generating twodifferent pseudo random number coded signals 3311 and 3312 to the firstcomponent 221 and the second component 222, respectively. The controller3310 may comprise analog and digital circuits, signal processor, genericcomputing processor, volatile or non-volatile memory for storinginstructions and data for the processor(s). The signal processor and/orprocessor may run on one or more instruction sets such as ARMinstruction set, Intel 8051 instruction set, and etc.

The battery 3330 may be rechargeable or non-rechargeable. The controller3310 may include charging circuits for the rechargeable battery 3330.Electrical power stored in the battery 3330 is supplied to thecontroller 3310 and the clock signal source 3320 for operations. Theclock signal module 3320 may be any kind of oscillator(s) which outputsone or more clock signals to the controller 3310. For example, theoscillator may be crystal oscillator, XO, TCXO, OCXO, or VCXO. Thecontroller 3310 may comprises frequency divider or frequency multiplierto generate clock signals for data and for carrier. As shown in FIG. 30,frequency of data codes is slower than the carrier signal. The clocksignal module 3320 are configured to provide one or more clock signalsfor the encoding process described.

Multiple pseudo random number (PN) codes are stored in the controller3310. A first PN code is corresponding to the signal 3311 and a secondPN code is corresponding to the signal 3312. All of these applicable PNcodes are orthogonal to each other. It means that any two of the PNcodes are orthogonal.

In one embodiment, mapping relationship between the signal 3311 and thePN code may be configurable and stored in the controller 3310. Forexample, there may be 10 PN codes stored in five active styli 111. Eachof the styli 111 is configured to use a set of two PN codes. Hence, fivesets of PN codes emitted from the styli 111 simultaneously can bedistinguished by the touch sensitive processing apparatus 130. Theposition of each of the styli 111 can be found according to theelectrical signal emitted from the tip section 230.

For providing configuration interface of the mapping relationship, thestylus 111 may include physical human-machine interface for input and/orouput. In one example, the stylus 111 may include visual and/or audioindicator for showing the set of PN codes that the controller 3310 use.The visual or audio indicator is connected and controlled by thecontroller 3310.

The visual indicator may include multiple light bulbs, LED, orequivalents, where each of the light is corresponding to each set of thePN codes. Alternatively, the visual indicator may include one LED whichflashes one or multiple times in a short period to show the configuredmapped set of the PN codes. Or the visual indicator may presentdifferent colors to show which set of the PN codes is configured.

Similaily, the audio indicator may include a beeper which may be used toprompt user by number of beeps in a short period. Or a speaker may beused to output voices and/or sounds to advertise the configured mappedset of the PN codes.

An input button, a switch or a knob of the stylus 111 may be used toconfigure the set of PN codes. The state of the button, the switch orthe knob may be used to indicate which set of the PN codes isconfigured.

Apart from the physical human-machine interface, the stylus 111 maycomprise a communication unit for receiving the configuration settingfrom remote machine to the controller 3310. The communication unit maybe compatible to wired or wireless industrial standards such asBluetooth, USB, Wireless USB, UWB, and etc. Persons having ordinaryskill in the art are able to understand similar communication units arewidely used in modern consumer electronics such as smartphone, mobilecomputer, and etc. For example, the transmitter wireless communicationunit 770 as shown in FIGS. 7A-7D may be used here.

A remote machine may be used to connect to the communication unit forreading and/or configuring the set of the PN codes. A configurationprogram may be run on the remote machine to read or to set the PN codesof the connected stylus 111. In one embodiment, the remote machine mayconnect to multiple styli 111 simultaneously for ensuring that each oneof the connected styli 111 use different set of PN codes. Once theremote machine detects that sets of the PN codes used by connected styli111 are conflicted, the remote machine may automatically assigndifferent sets of the PN codes to the conflicted styli 111.

In some embodiments, the set of PN codes used by the stylus 111 is fixedor hard-coded before shipping out of factory. The stylus 111 may bepainted in a particular color or a visual identification may be shown onthe stylus 111. Users may check colors or visual identifications oftheir styli 111. If they hold different colored styli 111, the touchsensitive processing apparatus 130 is able to identify each of the styli111.

The stylus 111 may comprise one or more human interfaces or sensors suchas buttons, knobs, attitude sensors, gyroscopes, accelerometers,electrical signal receiver, and etc. The status of these humaninterfaces and sensors can be collected periodically by the controller3310. The status or any other information such as a uniqueidentification code of the stylus 111 to be sent to the touch sensitiveprocessing apparatus 130 may be treated as data codes shown in FIG. 30.The data codes to be sent and the first PN code may be modulated by thecontroller 3310. A person having ordinary skill in the art canunderstand that CDMA or direct sequence spread spectrum technique iswidely used in the 3G telecommunication. The controller 3310 compriseshardwired circuits and/or embedded processor for modulation.Traditionally, a multiplier is used to generate the carrier signalaccording to the data code and the PN code. If there is no need to sendany data code, the signals 3311 and 3312 received by the tip section 230may be the first PN code and the second PN code, respectively.

The data codes may be modulated according to the first PN code togenerate the signal 3311. The data codes may be also modulated accordingto the second PN code to generate the signal 3312. In other words, thedata codes may be transmitted via one or both of the signals 3311 and3312. The touch sensitive processing apparatus 130 may despread ordecode the data codes emitted from the tip section 230 according to oneor both the first and the second PN codes. If the data codes decodedaccording to the first PN code is consistent with the data codes decodedaccording to the second PN code, the data codes are trustworthy.Otherwise, the two different data codes may be discarded or disregarded.

The active stylus 111 may further comprise a receiver forsynchronization with the touch sensitive processing apparatus 130. Asdescribed in the previous paragraphs, a beacon signal may be emitted viaelectrodes of the touch panel 120 by the touch sensitive processingapparatus 130 for synchronization. The tip section 230 may be served asa receiving antenna for receiving the beacon signal. Beacon signals asshown in FIGS. 9A˜9F may be adopted to this embodiment.

The controller 3310 may connect to the tip section 230 for receiving thebeacon signal. In order to correctly receive and identify the beaconsignal, the controller 3310 may include circuits such as integrator,sampler, amplifier, analog to digital converter, adder, and any othercircuits for receiving the beacon signal. The received signal may befurther processed by the processor to retrieve the synchronizationsignal and/or message carried by the beacon signal from interference.Once the beacon signal is received, the controller 3310 may transmit thesignals 3311 and 3312 to the tip section 230 after a predeterminedturnaround period which is known to the touch sensitive processingapparatus 130. Or the beacon signal may include a time period parameterto indicate length of the turnaround period.

If there are multiple styli 111 operating in the touch sensitive system100, the beacon signal with no turnaround time period would cause all ofthe styli 111 transmitting electrical signals in the same time. However,since the electrical signals transmitted by these styli 111 are encodedby different PN codes, the touch sensitive processing apparatus 130 candistinguish each of the styli 111.

In one embodiment, the beacon signal may further include anidentification corresponding to one of the styli 111 and a turnaroundtime period. If one of the styli 111 receives the beacon signalincluding its identification, the stylus 111 would transmit theelectrical signal via the tip section 230 at the designated turnaroundtime period indicated in the beacon signal. In order to prevent oralleviate interference in the touch sensitive system 100, the touchsensitive processing apparatus 130 may emit a beacon signal withmultiple combinations of stylus identifications and designatedturnaround time periods or time slots.

Alternatively, the touch sensitive processing apparatus 130 may transmitmultiple beacon signals for the styli 111. The beacon signals aremodulated differently. For example, the modulation of these beaconsignals may be varied in frequency, phase, amplitude and etc. Thereforeeach of the styli 111 can listen to its designated beacon signal.

In one embodiment, the touch sensitive system 100 may utilize multiplemodulations of beacon signal for multiple groups of styli 111. In eachmodulation of beacon signal, multiple combinations of stylusidentifications and designated turnaround timer periods or time slotsmay be included. The touch sensitive processing apparatus 130 maycontrol refresh rates of each modulation of beacon signal. If one of thestyli 111 goes idle, the beacon signal sent to the idle stylus 111 maybe delayed or omitted. If one of the styli 111 goes wildly, the touchsensitive processing apparatus 130 may send more beacon signal to thestylus 111 than the rest of the styli 111 in order to get the positionsand/or the data codes more frequently and precisely. Persons havingordinary skill in the art can understand that the touch sensitiveprocessing apparatus 130 may adjust the refresh/update rate of eachstylus 111 by controlling the transmission of the corresponding beaconsignal.

Alternatively, the beacon signal may be emitted by the host 140. Forexample, the touch sensitive processing apparatus 130 may use a wirelesscommunication unit equipped by the host 140 to transmit the beaconsignal. Based on nature of the wireless communication protocols, thebeacon signal may be broadcasted or unicasted to each of the styli 111.For example, Bluetooth protocol defines a broadcast mechanism to sendadvertising message. The beacon signal may be carried out by thebroadcast mechanism of Bluetooth protocol. Any stylus 111 receiving theadvertising message serving as the beacon signal is synchronizedaccordingly. Otherwise, the beacon signal may be unicasted wirelesslyfrom the host 140 to the stylus 111. Persons having ordinary skill inthe art can understand the synchronization between the stylus 111 andthe touch sensitive processing apparatus 130 is done by the beaconsignal which may be transmitted via the touch panel 120 or via wired orwireless communication channel in between.

Although the synchronization may be achieved by the beacon signal, thetouch sensitive processing apparatus 130 may synchronize the electricalsignal by itself. The controller 3310 may transmit signal with apreamble code via one or both of the first component 221 and the secondcomponent 222. The preamble code may be encoded by one or both the firstPN code and the second PN code. Eventually the electrical signal emittedvia the tip section 230 includes the preamble code and/or data codes.Once the touch sensitive processing apparatus 130 receives electricalsignal via the touch panel 120, the received electrical signal would beamplified, sampled, converted into digital forms and stored in thememory. Hence, circuits or processor embedded in the touch sensitiveprocessing apparatus 130 may compare the stored signal with the preamblecode corresponding to the stylus 111. In case the stored signal is fullyor partial matched with the preamble code, the touch sensitiveprocessing apparatus 130 is able to calculate the receiving timing ofthe stored preamble code. Consequently, timing of a next transmissionfrom the stylus 111 can be calculated by the touch sensitive processingapparatus 130 according to the stored preamble code. In some examples,the match of the preamble code is fast enough that the data codes in thesame transmission can be decoded; especially in case the preamble codeis sufficiently enduring. A sliding window mechanism on the memorystoring the received signal may be applied to find the preamble code.

When the preamble code is found, the touch sensitive processingapparatus 130 can calculate a position that the stylus 111 touching orapproaching the touch panel 120 according to the received signals. Iftwo or more styli 111 use different sets of the PN codes, the preamblecodes of these styli 111 are different and orthogonal. Even the preamblecodes are received simultaneously, the touch sensitive processingapparatus 130 are able to find out the positions of the styli 111touching or approaching the touch panel 120.

Referring to FIG. 34, it shows a block diagram of a touch sensitiveprocessing apparatus 130 according to an embodiment of the presentinvention. The touch sensitive processing apparatus 130 may include anembedded processor 3440, which is used for connecting and controlling aninterconnection network 3410, a driving circuit 3420, a sensing circuit3430, and a host interface 3450. The driving circuit 3420 mayrespectively connect each first electrode 121 and each second electrode122 via the interconnection network 3410 to use these electrodes to emita driving signal. The sensing circuit 3430 may respectively connect eachfirst electrode 121 and each second electrode 122 via theinterconnection network 3410 to use these electrodes to sense signal(s).The embedded processor 3440 can communicate with the host 140 throughthe host interface 3450. The embedded processor 3440 may perform aprogram module stored in non-volatile memory to detect theabovementioned approximate object(s) and event(s).

The interconnection network 3410 is dynamically configurable by theembedded processor 3440. The driving circuit 3420 may be connected toone or more of the first electrodes 121 and/or the second electrodes 122via the interconnection network 3410. Similarly, the sensing circuit3430 may be connected to one or more of the first electrodes 121 and/orthe second electrodes 122 via the interconnection network 3410. In oneembodiment, the driving circuit 3420 and the sensing circuit 3430 arecollectively called “analog frontend” circuits which may comprises anycombination of amplifiers, filters, samplers, integrator,digital-to-analog converter, analog-to-digital converter, adder,multiplier, variable resistors, and etc. Apart from the analog circuitsincluding the driving circuit 3420 and the sensing circuit 3430, theembedded processor 3440 may deal with digital parts of signalprocessing. The host interface 3450 is used to connect the embeddedprocessor 3440 and the host 140. Typically, the host interface 3450 maybe compatible to industrial standards such as USB, I2C, PCI,PCI-Express, SCSI, and etc. Persons with ordinary skill in the art canunderstand the host interface 3450 is very common in modern electronics.

Please refer to FIG. 35, which illustrates a flowchart diagram practicedby the controller 3310 as shown in FIG. 33 in accordance to anembodiment of the present invention. The flow may be also applicable tothe stylus 111 as shown in FIG. 33. Unless a causal relationship isnoted, the present invention does not limit execution sequences of anytwo of the steps as shown in FIG. 35.

Optional step 3510: receiving configuration setting of a first PN codeand a second PN code. The configuration mechanism is already described.

Optional step 3520: receiving a beacon signal. The touch sensitiveprocessing apparatus 130 may transmit the beacon signal via at least oneof the first electrodes 121 or the second electrodes 122 of the touchpanel 120 to the stylus 111. Alternatively, the touch sensitiveprocessing apparatus 130 may ask a communication unit of the host 140 totransmit the beacon signal to a corresponding communication unit of thestylus 111.

Optional Step 3530: decoding identification and turnaround time periodparameter. If the optional step 3520 is performed and a beacon signal isreceived, the beacon signal may comprise identification and/orturnaround time period parameter for a specified stylus 111 or aspecified group of styli 111. Thus, the identification of stylus 111and/or the turnaround time period specified in the beacon signal isdecoded.

Optional Step 3540: generating data codes according to status of onboardsensors. If the stylus 111 comprises one or more onboard sensors such asbutton, switch, knob, battery volume and etc. in additional to thepressure sensor connected to the first component 221, data codes may begenerated to reflect the status of onboard sensors and/or otherinformation such as the identification of the stylus 111, and/or modeland vendor name of the stylus 111.

Step 3550: transmitting a first preamble code and/or data codesaccording to the first PN code to a first component having variableimpedance reflecting a pressure. The transmitted signal may be the firstpreamble code, the data codes, or both of them. Since they are allencoded by the first PN code, the touch sensitive processing apparatus130 is able to detect and decode the transmitted signals via the tipsection 230 and the electrodes 121 and/or 122 in theory.

Step 3560: transmitting a second preamble code and/or data codesaccording to the second PN code to a second component having variableimpedance reflecting a pressure. The steps 3550 and 3560 may beperformed simultaneously. The transmitted signal may be the secondpreamble code, the data codes, or both of them. Since they are allencoded by the second PN code, the touch sensitive processing apparatus130 is able to detect and decode the transmitted signals via the tipsection 230 and the electrodes 121 and/or 122 in theory.

Please refer to FIG. 36A, which illustrates a flowchart diagrampracticed by the embedded processor 3440 in accordance to an embodimentof the present invention. The flow is applicable to the touch sensitiveprocessing apparatus 130 as shown in FIGS. 33 and 34. Unless a causalrelationship is noted, the present invention does not limit executionsequences of any two of the steps as shown in FIG. 36A. If a beaconsignal is used as a synchronization signal in the system 100, the flowbegins with the step 3610.

Optional step 3610: transmitting a beacon signal. This step iscorresponding to the step 3520 as shown in FIG. 35. The touch sensitiveprocessing apparatus 130 may transmit the beacon signal via at least oneof the first electrodes 121 or the second electrodes 122 of the touchpanel 120 to the stylus 111. Alternatively, the touch sensitiveprocessing apparatus 130 may ask a communication unit of the host 140 totransmit the beacon signal to a corresponding communication unit of thestylus 111. Optionally, the beacon signal may comprise one or moreidentifications and/or turnaround time period parameters for one oremore specified styli 111 or a specified group of styli 111.

Optional step 3620: waiting for a turnaround time period. If thetransmitted beacon signal indicates the turnaround time period, theembedded processor 3440 or the touch sensitive processing apparatus 130may wait or sleep in this period. Alternatively, the embedded processor3440 may perform other functions such as capacitive sensing for externalconductive objects touching or approaching the touch panel 120 in thisturnaround time period.

Step 3630: receiving electrical signals via electrodes of a touch panel.The stylus 111 transmits electrical signals via the tip section 230 toat least one of the electrodes 121 and 122 of the touch panel 120. Theelectrical signals are received by the sensing circuit 3430 of the touchsensitive processing apparatus 130 via the electrodes near the tipsection 230.

Optional step 3640: despreading a first preamble code of receivedelectrical signals in accordance with a first PN code. If the electricalsignals transmitted by the stylus 111 comprise the first preamble code,the embedded processor 3440 of the touch sensitive processing apparatus130 is able to despread the first preamble code in accordance with thefirst PN code. In some embodiments, the system 100 does not utilize thebeacon signal to synchronize the timing of transmitting electricalsignals, i.e., the steps 3610 and 3620 are omitted, the embeddedprocessor 3440 may be required to use sliding window technique toacquire the first preamble code in the received electrical signalsbecause the embedded processor 3440 has no idea when the electricalsignals would be transmitted by the stylus 111.

Optional step 3650: decoding first data codes of received signals inaccordance with the first PN code. If the electrical signals transmittedby the stylus 111 comprise the first data codes, the embedded processor3440 of the touch sensitive processing apparatus 130 is able to decodethe first data codes in accordance with the first PN code. Embodimentsof the present application may include one or both of the steps 3640 and3650.

Optional step 3660: despreading a second preamble code of receivedelectrical signals in accordance with a second PN code. If theelectrical signals transmitted by the stylus 111 comprise the secondpreamble code, the embedded processor 3440 of the touch sensitiveprocessing apparatus 130 is able to despread the second preamble code inaccordance with the first PN code. In some embodiments, the system 100does not utilize the beacon signal to synchronize the timing oftransmitting electrical signals, i.e., the steps 3610 and 3620 areomitted, the embedded processor 3440 may be required to use slidingwindow technique to acquire the second preamble code in the receivedelectrical signals because the embedded processor 3440 has no idea whenthe electrical signals would be transmitted by the stylus 111.

Optional step 3670: decoding second data codes of received signals inaccordance with the second PN code. If the electrical signalstransmitted by the stylus 111 comprise the second data codes, theembedded processor 3440 of the touch sensitive processing apparatus 130is able to decode the second data codes in accordance with the second PNcode. Embodiments of the present application may include one or both ofthe steps 3660 and 3670.

In order to save design complexity, the controller 3310 may encode thedata codes reflecting status of onboard sensors in one of the signals3311 and 3312. Thus, it just needs to perform one of the steps 3650 and3670 accordingly as well as the steps 3640 and 3660.

In order to increase transmission reliability, the controller 3310 mayencode the data codes in both of the signals 3311 and 3312. The steps3650 and 3670 may be performed accordingly to retrieve the first datacodes and the second data codes. In one embodiment, the flow may furtherinclude a comparison step for comparing the first data codes and thesecond data codes. If these two data codes are inconsistent, the flowmay drop out these two data codes because errors apparently happened inthe transmission. However, in order to save design complexity, the flowmay just include one of the steps 3650 and 3670 although the stylus 111encode the data codes in both the signals 3311 and 3312.

In the embodiments lacking of beacon signals, if the timing ofelectrical signals transmitted by the stylus 111 is found at steps 3640or 3650, the step 3660 and/or the step 3670 may be performed accordingto the found timing. In other words, the synchronization is built.Reversely, if the timing of electrical signals is found at steps 3660 or3670, the step 3640 and/or the step 3650 may be performed according tothe found timing. In other words, in order to synchronize with thestylus 111, the embedded processor 3440 just need to execute one slidingwindow algorithm to acquire one of the first and second preamble codesand the first and the second data codes. Otherwise, the steps 3640-3670may be performed simultaneously or independently in an embodimentalthough sliding windows algorithms may be executed more than once.

Step 3680: calculating a pressure according to signal strength ratio ofa first part corresponding to the first PN code and a second partcorresponding to the second PN code. The first part corresponding to thefirst PN code may be one or both of the first preamble code and thefirst data codes. Similarly, the second part corresponding to the secondPN code may be one or both of the second preamble code and the seconddata codes. If the electrical signals comprise the first preamble codeand the second preamble code, the step 3680 may be calculating thepressure reflecting to a pressure sensor of the stylus according tosignal strength ratio of the first preamble code and the second preamblecode. In case the electrical signals comprise the first data codes andthe second data codes, the step 3680 may be calculating the pressurereflecting to a pressure sensor of the stylus according to signalstrength ratio of the first data codes and the second data codes. In avariant, if the electrical signals comprise all four codes, the step3680 may be calculating the pressure reflecting to a pressure sensor ofthe stylus according to signal strength ratio between the first part andthe second part. Assume that the signal strength of the first part is M1and the signal strength of the second part is M2, the ratio of these twosignal strengths may be M1/M2, M2/M1, (M1−M2)/(M1+M2), (M2−M1)/(M1+M2),M1/(M1+M2), M2/(M1+M2) and any other calculations involving these twoparameters M1 and M2. In order words, if the calculated ratio is aconstant or a predetermined value, it is concluded that the pressuresensor of the stylus 111 does not sense any pressure. If the pressuresensor is configured to receive a pressure on the tip section 230 of thestylus 111, it means that the tip section 230 of the stylus 111 does nottouch anything including the touch panel 120.

When the tip section 230 of the stylus 111 contacts the touch panel 120,the tip section 230 is pressed to move. The first impedance Z1 of thefirst component 221 changes according to the movement or the pressure ofthe tip section 230 such that the ratio of M1 and M2 is variedaccordingly from the constant or the predetermined value. The touchsensitive processing apparatus 130 could generate corresponding sensing(pressure) value according to the ratio. The afore-mentioned constant orpredetermined value may not be a number but a range with a tolerableerror.

By realizing well-known algorithm in the art, the touch sensitiveprocessing apparatus 130 may calculate a position on the touch panelwhere the tip section 230 of the stylus 111 touching or approachingaccording to the electrical signals received by at least one of thefirst electrodes 121 and at least one of the second electrodes 122.Thus, the position, the pressure, status of the onboard sensors and/orany other information of the stylus 111 may be received by the touchsensitive processing apparatus 130. Consequently, the informationreceived by the touch sensitive processing apparatus 130 may beforwarded to an operating system as well as application programs run onthe host 140.

Please refer to FIG. 36B, which illustrates another flowchart diagrampracticed by the embedded processor 3440 in accordance to an embodimentof the present invention. The flow is applicable to the touch sensitiveprocessing apparatus 130 as shown in FIGS. 33 and 34. Unless a causalrelationship is noted, the present invention does not limit executionsequences of any two of the steps as shown in FIG. 36B. If a beaconsignal is used as a synchronization signal in the system 100, the flowbegins with the step 3610.

The differences between the flowcharts as shown in FIGS. 36A and 36B arethe steps 3630 through 3670 are replaced by the steps 3210 through 3250as described in FIG. 32. One of the purposes of the flow3200 is toaccelerate the acquisition of preamble codes of one or more styli bycouplding at least two of the second electrodes as a synchronizationchannel. In other words, the touch sensitive processing apparatus 130 isconfigured to synchronize the stylus without the beacon signalmechanism. Although the flow illustrated in FIG. 36B comprises optionalsteps 3610 and 3620, these two steps may also serve in a touch sensitivesystem 100 which comprises at least one stylus 111 which listens to thebeacon signal while other stylus 111 does not synchronize the beaconsignal. In other words, the touch sensitive processing apparatus 130 maybe configured to operate with different styli 111 which may or may nothave beacon signal receiver simultaneously. Although it demands moreprocessing capability and more memory space for storing electricalsignals to the touch sensitive processing apparatus 130, theinteroperability of such touch system 100 is increased significantly.

By comparing the timing of transmitting the electrical signals and theturnaround time period indicated in the beacon signal, the touchsensitive processing apparatus 130 may detect one stylus 111 having nobeacon signal synchronization capability because the timing isinconsistent with the indicated turnaround time period.

If the touch system 100 comprises a stylus 111 having beacon signalsynchronization capability and another stylus 111 having no suchcapability, the touch sensitive processing apparatus 130 may adjust thetiming of the beacon signal and/or the turnaround time period indicatedin the beacon signal to have these two styli 111 transmitting theirelectrical signals simultaneously so as to minimize the time periodspent in the receiving electrical signals from the styli 111 and tomaximize the time period for detecting external conductive objects suchas fingers. Alternatively, the touch sensitive processing apparatus 130may adjust the timing of the beacon signal and/or the turnaround timeperiod indicated in the beacon signal to have these two styli 111transmitting their electrical signals in non-overlapping periods so asto minimize the interferences between the two electrical signals.Moreover, since the electrical signal emitted by the stylus caninterfere with the reception of the beacon signal, the touch sensitiveprocessing apparatus 130 may adjust the timing of the beacon signaland/or the turnaround time period indicated in the beacon signal toalleviate or to eliminate the interference between the beacon signal andthe electrical signal transmitted from the stylus.

In the embodiments as shown in FIGS. 35, 36A and 36B, two PN codes isassigned to each of the stylus 111. Hence, the touch sensitiveprocessing apparatus 130 is able to identify all styli 111 whichtransmit electrical signals simultaneously. However, unlike the touchsensitive processing apparatus 130, computing resources and internalspace of the stylus 111 is quite limited. It may be desired to decreasecomputing complexity of the controller 3310. Hence, the controller 3310of the stylus 111 as shown in FIG. 33 may transmit the same electricalsignals 3311 and 3312 encoded by one PN code in two different timeperiods, respectively. As long as each stylus 111 in one touch system100 has different PN code, the touch sensitive processing apparatus 130is able to identify all styli 111 which may transmit electrical signalssimultaneously. With regard to electrical signals from the same stylus111 in two different time periods, the touch sensitive processingapparatus 130 is able to calculate a pressure according to signalstrength ratio of these two time periods. Furthermore, the controller3310 may collect status of the onboard sensors of the stylus 111 twiceto generate two data codes before transmitting them through the tipsection 230. By decreasing the number of PN codes from two to one, thedesign complexity of the controller 3310 is reduced consequently.

Please refer to FIG. 37A, which illustrates a flowchart diagrampracticed by the controller 3310 as shown in FIG. 33 in accordance to anembodiment of the present invention. The flow may be also applicable tothe stylus 111 as shown in FIG. 33. Unless a causal relationship isnoted, the present invention does not limit execution sequences of anytwo of the steps as shown in FIG. 37A. Steps 3520, 3530 and 3540 areexplained above in the paragraphs regarding to the flowchart as shown inFIG. 35.

Optional step 3710: receiving configuration setting of a PN code. Theconfiguration mechanism is already described.

Step 3750: transmitting a preamble code and/or data codes according tothe PN code to a first component having variable impedance reflecting apressure in a first time period. The transmitted signal may be thepreamble code, the data codes, or both of them. Since they are allencoded by the assigned PN code, the touch sensitive processingapparatus 130 is able to detect and decode the transmitted signals viathe tip section 230 and the electrodes 121 and/or 122 in the first timeperiod.

Step 3760: transmitting the preamble code and/or data codes according tothe PN code to a second component having fixed impedance in a secondtime period. The transmitted signal may be the preamble code, the datacodes, or both of them. Since they are all encoded by the assigned PNcode, the touch sensitive processing apparatus 130 is able to detect anddecode the transmitted signals via the tip section 230 and theelectrodes 121 and/or 122 in the second time period.

In one embodiment, a turnaround time period between the first timeperiod and the second time period may exist. During this turnaroundtimer period, the controller 3310 may switch signal output from thefirst component 221 to the second component 222.

Please refer to FIG. 37B, which illustrates another flowchart diagrampracticed by the controller 3310 as shown in FIG. 33 in accordance to anembodiment of the present invention. The flow may be also applicable tothe stylus 111 as shown in FIG. 33. Unless a causal relationship isnoted, the present invention does not limit execution sequences of anytwo of the steps as shown in FIG. 37.

Optional step 3745: generating first data codes according to status ofonboard sensors. If the stylus 111 comprises one or more onboard sensorssuch as button, switch, knob, battery volume and etc. in additional tothe pressure sensor connected to the first component 221, data codes maybe generated to reflect the status of onboard sensors and/or otherinformation such as the identification of the stylus 111, and/or modeland vendor name of the stylus 111.

Step 3755: transmitting a preamble code and/or first data codesaccording to the PN code to a first component having variable impedancereflecting a pressure in a first time period. The transmitted signal maybe the preamble code, the first data codes, or both of them. Since theyare all encoded by the assigned PN code, the touch sensitive processingapparatus 130 is able to detect and decode the transmitted signals viathe tip section 230 and the electrodes 121 and/or 122 in the first timeperiod. After step 3755, the flow may go to optional step 3746 forgenerating another data codes.

Optional step 3746: generating second data codes according to status ofonboard sensors.

Step 3765: transmitting the preamble code and/or second data codesaccording to the PN code to a second component having fixed impedance ina second time period. The transmitted signal may be the preamble code,the second data codes, or both of them. Since they are all encoded bythe assigned PN code, the touch sensitive processing apparatus 130 isable to detect and decode the transmitted signals via the tip section230 and the electrodes 121 and/or 122 in the second time period.

Although in the flowchart as shown in FIG. 37A, the flow executes thestep 3750 before the step 3760. Persons having ordinary skill in the artcan understand that the sequence of steps 3750 and 3760 may be reversed.The flow may go to the step 3760 from the step 3540 in some embodiments.Then the flow may go to the step 3750 after the step 3760. Similarly, inthe flowchart as shown in FIG. 37B, the flow may go to the steps 3746and 3765 from the step 3530. Then the flow may go to the steps 3745 and3755 after the step 3765. In short, the present invention does notrequire which one of the signals 3311 and 3312 is first sent out fromthe controller 3310.

Please refer to FIG. 38A, which illustrates a flowchart diagrampracticed by the embedded processor 3440 in accordance to an embodimentof the present invention. Adapting to the flowcharts embodied by one ormore styli 111 as shown in FIGS. 37A and 37B, the flow is applicable tothe touch sensitive processing apparatus 130 as shown in FIGS. 33 and34. Unless a causal relationship is noted, the present invention doesnot limit execution sequences of any two of the steps as shown in FIG.38A. If a beacon signal is used as a synchronization signal in thesystem 100, the flow begins with the step 3610. Two steps 3610 and 3620are described in the paragraphs with regard to the embodiment as shownin FIG. 36A. The flow may go to step 3830 after step 3620 is executed.

Step 3830: receiving electrical signals via electrodes of a touch panelin a first and a second time periods. The step 3830 may be performedconcurrently with any of the steps 3850 through 3870 during the secondtime period. The electrical signals are received by the sensing circuit3430 of the touch sensitive processing apparatus 130 via the electrodesnear the tip section 230. The electrical signals received in twodifferent time periods are stored, respectively.

Optional step 3840: despreading a first preamble code of electricalsignals received in the first time period in accordance with a PN code.If the electrical signals transmitted by the stylus 111 comprise thefirst preamble code, the embedded processor 3440 of the touch sensitiveprocessing apparatus 130 is able to despread the first preamble code inaccordance with the PN code. In some embodiments, the system 100 doesnot utilize the beacon signal to synchronize the timing of transmittingelectrical signals, i.e., the steps 3610 and 3620 are omitted, theembedded processor 3440 may be required to use sliding window techniqueto acquire the preamble code in the received electrical signals becausethe embedded processor 3440 has no idea when the electrical signalswould be transmitted by the stylus 111.

Optional step 3850: decoding first data codes of electrical signalsreceived in the first time period in accordance with the PN code. If theelectrical signals transmitted by the stylus 111 comprise the first datacodes, the embedded processor 3440 of the touch sensitive processingapparatus 130 is able to decode the first data codes in accordance withthe PN code corresponding to the stylus 111. Embodiments of the presentapplication may include one or both of the steps 3840 and 3850.

Optional step 3860: despreading a second preamble code of electricalsignals received in the second time period in accordance with a PN code.If the electrical signals transmitted by the stylus 111 comprise thesecond preamble code, the embedded processor 3440 of the touch sensitiveprocessing apparatus 130 is able to despread the second preamble code inaccordance with the PN code. Please be aware that since the first andthe second preamble codes are encoded by the same PN code, they shouldbe the same if their signal strengths are disregarded. In someembodiments, the system 100 does not utilize the beacon signal tosynchronize the timing of transmitting electrical signals, i.e., thesteps 3610 and 3620 are omitted, the embedded processor 3440 may berequired to use sliding window technique to acquire the preamble code inthe received electrical signals because the embedded processor 3440 hasno idea when the electrical signals would be transmitted by the stylus111.

Optional 3870: decoding second data codes of electrical signals receivedin the first time period in accordance with the PN code. If theelectrical signals transmitted by the stylus 111 comprise the seconddata codes, the embedded processor 3440 of the touch sensitiveprocessing apparatus 130 is able to decode the second data codes inaccordance with the PN code corresponding to the stylus 111. Embodimentsof the present application may include one or both of the steps 3860 and3870.

As described in the embodiment as shown in FIG. 37B, the controller 3310may generate two data codes for the two transmissions in the two timeperiods. If the first data codes are different from the data codes, ittells that the status of the onboard sensors was changed between the twogenerations. Apparently, the positions of the stylus 111 may also changebetween the two generations. Therefore the touch sensitive processingapparatus 130 may calculate a first position and a second positionaccording to the electrical signals received during the first timeperiod and the second time period accordingly. Or the touch sensitiveprocessing apparatus 130 may calculate only one position according toeither one of the electrical signals received during the first timeperiod or received during the second time period.

Step 3880: calculating a pressure according to signal strength ratio ofa first part received in the first time period and a second partreceived in the second time period. The first part of electrical signalsreceived in the first time period may be one or both of the firstpreamble code and first data codes. Similarly, the second part ofelectrical signals received in the second time period may be one or bothof the second preamble code and second data codes. If the electricalsignals comprise the first preamble code and the second preamble code,the step 3880 may be calculating the pressure reflecting to a pressuresensor of the stylus according to signal strength ratio of the firstpreamble code and the second preamble code. In case the electricalsignals comprise the first data codes and the second data codes, thestep 3880 may be calculating the pressure reflecting to a pressuresensor of the stylus according to signal strength ratio of the firstdata codes and the second data codes. In a variant, if the electricalsignals comprise all four codes, the step 3880 may be calculating thepressure reflecting to a pressure sensor of the stylus according tosignal strength ratio between the first part received in the first timeperiod and the second part received in the second time period. Assumethat the signal strength of the first part is M1 and the signal strengthof the second part is M2, the ratio of these two signal strengths may beM1/M2, M2/M1, (M1−M2)/(M1+M2), (M2−M1)/(M1+M2), M1/(M1+M2), M2/(M1+M2)and any other calculations involving these two parameters M1 and M2. Inorder words, if the calculated ratio is a constant or a predeterminedvalue, it is concluded that the pressure sensor of the stylus 111 doesnot sense any pressure. If the pressure sensor is configured to receivea pressure on the tip section 230 of the stylus 111, it means that thetip section 230 of the stylus 111 does not touch anything including thetouch panel 120.

Please refer to FIG. 38B , which illustrates a flowchart diagrampracticed by the embedded processor 3440 in accordance to an embodimentof the present invention. Adapting to the flowcharts embodied by one ormore styli 111 as shown in FIGS. 37A and 37B, the flow is applicable tothe touch sensitive processing apparatus 130 as shown in FIGS. 33 and34. Unless a causal relationship is noted, the present invention doesnot limit execution sequences of any two of the steps as shown in FIG.38B. If a beacon signal is used as a synchronization signal in thesystem 100, the flow begins with the step 3610. Two steps 3610 and 3620are described in the paragraphs with regard to the embodiment as shownin FIG. 36B. The flow may go to step 3210 after step 3620 is executed.

Optional step 3815: despreading a first preamble code of a first signalframe of received in a first timer period from the synchronizationchannel to retrieve a first synchronization information according to apseudo noise code.

Optional step 3825: decoding first data codes behind the first preamblecode of electrical signal received in the first time period from at leatone of the first electrodes in accordance with the first synchronizationinformation and the PN code.

Optional step 3835: despreading a second preamble code of a secondsignal frame of received in a second timer period from thesynchronization channel to retrieve a second synchronization informationaccording to the PN code.

Optional step 3845: decoding second data codes behind the secondpreamble code of electrical signal received in the second time periodfrom at leat one of the first electrodes in accordance with the secondsynchronization information and the PN code.

In an embodiment, once the first synchronization information with regardto the first time period is known, the second synchronizationinformation could be calculated accordingly.

In an embodiment, Please be aware that since the first and the secondpreamble codes are encoded by the same PN code, they should be the sameif their signal strengths are disregarded. In some embodiments, thesystem 100 does not utilize the beacon signal to synchronize the timingof transmitting electrical signals, i.e., the steps 3610 and 3620 areomitted, the embedded processor 3440 may be required to use slidingwindow technique to acquire the preamble code in the received electricalsignals because the embedded processor 3440 has no idea when theelectrical signals would be transmitted by the stylus 111.

As described in the embodiment as shown in FIG. 37B, the controller 3310may generate two data codes for the two transmissions in the two timeperiods. If the first data codes are different from the data codes, ittells that the status of the onboard sensors was changed between the twogenerations. Apparently, the positions of the stylus 111 may also changebetween the two generations. Therefore the touch sensitive processingapparatus 130 may calculate a first position and a second positionaccording to the electrical signals received during the first timeperiod and the second time period accordingly. Or the touch sensitiveprocessing apparatus 130 may calculate only one position according toeither one of the electrical signals received during the first timeperiod or received during the second time period.

Step 3880: calculating a pressure according to signal strength ratio ofa first part received in the first time period and a second partreceived in the second time period. The first part may be one or both ofthe first preamble code and the first data codes. Similarly, the secondpart may be one or both of the second preamble code and the second datacodes. If the electrical signals comprise the first preamble code andthe second preamble code, the step 3880 may be calculating the pressurereflecting to a pressure sensor of the stylus according to signalstrength ratio of the first preamble code and the second preamble code.In case the electrical signals comprise the first data codes and thesecond data codes, the step 3880 may be calculating the pressurereflecting to a pressure sensor of the stylus according to signalstrength ratio of the first data codes and the second data codes. In avariant, if the electrical signals comprise all four codes, the step3880 may be calculating the pressure reflecting to a pressure sensor ofthe stylus according to signal strength ratio between the first partreceived in the first time period and the second part received in thesecond time period. Assume that the signal strength of the first part isM1 and the signal strength of the second part is M2, the ratio of thesetwo signal strengths may be M1/M2, M2/M1, (M1−M2)/(M1+M2),(M2−M1)/(M1+M2), M1/(M1+M2), M2/(M1+M2) and any other calculationsinvolving these two parameters M1 and M2. In order words, if thecalculated ratio is a constant or a predetermined value, it is concludedthat the pressure sensor of the stylus 111 does not sense any pressure.If the pressure sensor is configured to receive a pressure on the tipsection 230 of the stylus 111, it means that the tip section 230 of thestylus 111 does not touch anything including the touch panel 120.

In real word scenarios, it is not uncommon to get lost of a wirelessstylus 111. Besides, it may need to recharge battery of the wirelessstylus 111 quite often. In some scenarios, it is desired to have one ormore corded styli which physically connect to the touch system.Utilizing the same mechanism of PN codes, the touch sensitive processingapparatus can select its own timing to transmit signals to corded stylusand to receive the signals from the touch panel 120. This mechanism isable to omit the synchronization mechanism between the wireless stylus111 and the touch sensitive processing apparatus 130.

Please refer to FIG. 39A, which illustrates a schematic diagram of atouch system 3900 in accordance with an embodiment of the presentinvention. The touch system 3900 may comprises the touch panel 120, thetouch sensitive processing apparatus 130, the host 140, and a cordedstylus 3910. The corded stylus 3910 may comprises the first component221 with variable first impedance Z1 which reflects to a pressure to thefirst component 221, the second component 222 with fixed secondimpedance Z2, the tip section 230 which is coupled to the outputs of thefirst component 221 and the second component 222, and a shell or acontainer which encapsulates the first component 221, the secondcomponent 222 and the tip section 230. A cord is used to connect thestylus 3910 and the touch sensitive processing apparatus 130. The cordmay be a twisted and shielded cable which may include a first signalcircuit 3911, a second signal citcuit 3912, and a third circuit 3913. Inone embodiment, the third line 3913 may be electrically coupled to theshell which may be grounded if a user holds the stylus 3910 by hand. Inaddition, the third line 3913 may be electrically coupled to a groundpotential port of the touch sensitive processing apparatus 130.

Although there is only one corded stylus 3910 shown in FIG. 39A, theremay be multiple corded styli 3910 connecting to the touch sensitiveprocessing apparatus 130 in some embodiments of the present invention.Based on the proposed mechanism, the multiple corded styli 3910 canoperate simultaneously. More importantly, a touch system of embodimentsin accordance with the present invention may comprise wireless andcorded styli. Persons having ordinary skill art can understand the touchsensitive processing apparatus 130 may use the synchronization mechanismto have the wireless stylus 111 transmit electrical signals at the sametime while the touch sensitive processing apparatus 130 transmitselectrical signals via the corded stylus 3910 if the electrical signalssimultaneously transmitted from each of the wireless and corded styliare encoded by different sets of PN codes.

The corded stylus 3910 as shown in FIG. 39A does not include a switch ora button. However, a corded stylus 3910 may comprise one or more onboardsensors such as a switch or a button for receiving user's input. In oneembodiment, each of the onboard sensors may connect to the touchsensitive processing apparatus 130 via one or more circuits included inthe cord. Hence, the status of the onboard sensor may be detected by thetouch sensitive processing apparatus 130 via the cord. For example, thetouch sensitive processing apparatus 130 may detect whether an eraserbutton is pressed or not via one or more circuits connecting to theeraser button. However, just similar to the embodiments as shown inFIGS. 4A and 4B, the corded stylus 3910 may further comprise a switchand a corresponding component which is connected in parallel with thefirst or the second components. The touch sensitive processing apparatus130 is able to tell the status of the switch of the stylus 3910according to a ratio of signal strength between the two PN codes.

Please refer to FIG. 39B, which illustrates a schematic diagram of avariant of the touch system 3900 in accordance with an embodiment of thepresent invention. The stylus 3910 may further comprise a third switch3920 and a third component 3930 which are connected in parallel to thefirst component 221. The third component 3930 may be a circuit such as aresistance and/or a capacitor with third impedance Z 3. When the thirdswitch 3920 is closed by a user of the stylus 3910, the signal driven bythe signal circuit 3911 propagates through the first component 221 andthe third component 3930 to the tip section 230. Reversely, when thethird switch 3920 is opened by the user, the signal driven by the signalcircuit 3911 propagates through the first component 221 to the tipsection 230. The signal driven by the signal circuit 3912 propagatesthrough the second component 222 to the tip section 230. After receivingthe signals driven by the signal circuits 3911 and 3912 emitted from thetip section 230, the touch sensitive processing apparatus 130 is able totell the status of the third switch 3920 of the stylus 3910 according toa ratio of signal strength between the two signals driven by the signalcircuits 3911 and 3912. If the ratio is fallen into a first interval,the touch sensitive processing apparatus 130 determines that the thirdswitch 3920 is being opened. If the ratio is fallen into a secondinterval, the touch sensitive processing apparatus 130 determines thatthe third switch 3920 is being closed. The third impedancecharacteristics of the third component 3930 may be configured such thatthe first interval is not interleaved with the second interval.Moreover, the touch sensitive processing apparatus 130 may be able tocalculate the pressure on the first component 221 according to the ratiowhich may be fallen into the first interval or the second interval.

Please refer back to FIG. 4A. The active stylus 110 comprises twoswitches SWE and SWB, the eraser capacitor 441 corresponding to theswitch SWE and the barrel capacitor 442 corresponding to the switch SWB.They are arranged in parallel with the first capacitor 321. Although thecorded stylus 3910 as shown in FIG. 39B comprises only one third swtich3920 and one corresponding third component 3930, persons with ordinaryskill in the art may understand that the corded stylus 3910 may havemore than one set of third switch 3920 and corresponding third component3930 which are arranged in parallel with the first component 221.

Please refer to FIG. 39C, which illustrates a schematic diagram of avariant of the touch system 3900 in accordance with an embodiment of thepresent invention. The stylus 3910 may further comprise a fourth switch3940 and a fourth component 3950 which are connected in parallel to thesecond component 222. The fourth component 3950 may be a circuit such asa resistance and/or a capacitor with fourth impedance Z 4. When thefourth switch 3940 is closed by a user of the stylus 3910, the signaldriven by the signal circuit 3912 propagates through the secondcomponent 222 and the fourth component 3950 to the tip section 230.Reversely, when the fourth switch 3940 is opened by the user, the signaldriven by the signal circuit 3912 propagates through the secondcomponent 222 to the tip section 230. The signal driven by the signalcircuit 3911 propagates through the first component 221 to the tipsection 230. After receiving the signals driven by the signal circuit3911 and 3912 emitted from the tip section 230, the touch sensitiveprocessing apparatus 130 is able to tell the status of the fourth switch3940 of the stylus 3910 according to a ratio of signal strength betweenthe two signals driven by the signal circuit 3911 and 3912. If the ratiois fallen into a third interval, the touch sensitive processingapparatus 130 determines that the fourth switch 3940 is being opened. Ifthe ratio is fallen into a fourth interval, the touch sensitiveprocessing apparatus 130 determines that the fourth switch 3940 is beingclosed. The fourth impedance characteristics of the fourth component3950 may be configured such that the third interval is not interleavedwith the fourth interval. Moreover, the touch sensitive processingapparatus 130 may be able to calculate the pressure on the firstcomponent 221 according to the ratio which may be fallen into the thirdinterval or the fourth interval.

Please refer back to FIG. 4B. The active stylus 110 comprises twoswitches SWE and SWB, the eraser capacitor 441 corresponding to theswitch SWE and the barrel capacitor 442 corresponding to the switch SWB.They are arranged in parallel with the second capacitor 322. Althoughthe corded stylus 3910 as shown in FIG. 39C comprises only one fourthswtich 3940 and one corresponding fourth component 3960, persons withordinary skill in the art may understand that the corded stylus 3910 mayhave more than one set of fourth switch and corresponding fourthcomponent which are arranged in parallel with the second component 221.

In one embodiment, the touch sensitive processing apparatus 130 mayconcurrently transmits the signals via the signal circuits 3911 and 3912to the stylus 3910 which are encoded according to a first PN code and asecond PN code, respectively. Therefore, the touch sensitive processingapparatus 130 may receive the signals driven by the signal circuits 3911and 3912 from the touch panel 120 concurrently. In another embodiment,the touch sensitive processing apparatus 130 may transmits the signalsvia the signal circuits 3911 and 3912 to the stylus 3910 which areencoded according to one PN code in a time-sharing manner. Therefore,the touch sensitive processing apparatus 130 may receive the signalsdriven by the signal circuits 3911 and 3912 from the touch panel 120 intwo time periods, respectively. In both embodiments, the touch sensitiveprocessing apparatus 130 may be able to determine the status of thethird switch 3920 or the fourth switch 3940 according to the ratio ofthe signals driven by the signal circuits 3911 and 3912. Moreover, thetouch sensitive processing apparatus 130 may be able to calculate thepressure on the first component 221 according to the ratio of thesignals driven by the signal circuits 3911 and 3912.

Please refer to FIG. 40, which depicts a schematic diagram of a touchsensitive processing apparatus 130 in accordance with an embodiment ofthe invention. Comparing with the touch sensitive processing apparatus130 as shown in FIG. 34, the touch sensitive processing apparatus 130further comprise one or more stylus interface 4010 which is coupled tothe interconnection network 3410. The stylus interface 4010 may becompatible to existing industrial standard or a proprietary interfacewhich includes three circuits 3911, 3912 and 3913 corresponding to oneof the stylus 3910. For one stylus 3910, there is one correspondingstylus interface 4010.

The touch sensitive processing apparatus 130 may further include anembedded processor 4040 which is configured to generate signals encodedby one or more pseudo-random number codes corresponding to each stylus3910. The generated signals may be sent to the driving circuit 3420 forfront-end analog processing. And the interconnection network 3410 isfurther configured by the embedded processor 4040 to selectively connectthe driving circuit 3420 to at least one of the signal circuits 3911 and3912. Therefore the signals encoded by PN code is transmitted to the tipsection 230 of the corresponding stylus 3910 which connects to thestylus interface 4010.

Moreover, the interconnection network 3410 is further configured by theembedded processor 4040 to connect the sensing circuit 3430 and theelectrodes of the touch panel 120. If the tip section 230 of thecorresponding stylus 3910 is placed on or near the touch panel, thesignals emitted by the tip section 230 would be received by the sensingcircuit 3430 via the electrodes of the touch panel 120. After doingfront-end analog processing and analog-to-digital conversion, theembedded processor 4040 receives the signals from the sensing circuit3430. Person having ordinary skill in the art can understand that theembedded processor 4040 is able to calculate the received signalstrengths corresponding to the signals sent to the signal circuits 3911and 3912, respectively, according to the received signals. Thus, a ratioof the signal strength can be calculated accordingly. As explained inprevious paragraphs, based on the received signals and the ratio, theembedded processor 4040 may be able to determine three parameters: thepressure received by the stylus 3910; the status of a switch of thestylus 3910; and a position where the tip section 230 of the stylus 3910touching or approaching the touch panel 120.

Please refer to FIG. 41A, which illustrates a flowchart diagram of anoperating method applicable to a corded stylus of an embodimentaccording to the invention. The flowchart is especially applicable tothe corded stylus 3910 as shown in FIG. 39A. Unless a causalrelationship is noted, the present invention does not limit executionsequences of any two of the steps as shown in FIG. 41A.

Step 4110: receiving a first preamble code according to a first PN codeby a first component having variable impedance reflecting a pressure. Asshown in FIG. 39A, the first component 221 of the stylus 3910 receivesthe first preamble code via the signal circuit 3911.

Step 4120: receiving a second preamble code according to a second PNcode by a second component having fixed impedance. As shown in FIG. 39A,the second component 222 of the stylus 3910 receives the second preamblecode via the signal circuit 3912. The steps 4110 and 4120 may be beingperformed concurrently or in a time-sharing manner.

Step 4130: transmitting the first preamble code by the first componentto a tip section.

Step 4140: transmitting the second preamble code by the second componentto the tip section. If the steps 4110 and 4120 are being performedconcurrently, the steps 4130 and 4140 are also being performedconcurrently. Or, all these four steps 4110 through 4140 are beingperformed concurrently.

If the touch sensitive processing apparatus 130 connects to multiplestyli 3910, a set of two PN codes can be assigned to each stylus 3910.For example, a set including a first PN code and a second PN code isassigned to a first corded stylus 3910 and another set including a thirdPN code and a fourth PN code is assigned to a second corded stylus 3910.The flowchart diagram as shown in FIG. 41A is applicable to the firstand the second corded styli 3910. In other words, two corded styli 3910can operate on one touch panel 120 concurrently.

Please refer to FIG. 41B, which illustrates a flowchart diagram of anoperating method applicable to a corded stylus of an embodimentaccording to the invention. The flowchart is especially applicable tothe corded stylus 3910 as shown in FIG. 39B. Unless a causalrelationship is noted, the present invention does not limit executionsequences of any two of the steps as shown in FIG. 41B. Because thecorded stylus 3910 as shown in FIG. 39B comprises the third switch 3920and the third component 3930, the flowchart further comprises steps 4122and 4124.

Step 4122: selectively receiving the first preamble code by a thirdcomponent which is connected in parallel with the first component. Theselectively receiving is carried out by the third switch 3920 as shownin FIG. 39B.

Step 4124: selectively transmitting the first preamble code by the thirdcomponent to a tip section. The selective transmitting is also carriedout by the third switch 3920 as shown in FIG. 39B. The steps 4110, 4120,4122 and 4124 may be being performed concurrently.

Please refer to FIG. 41C, which illustrates a flowchart diagram of anoperating method applicable to a corded stylus of an embodimentaccording to the invention. The flowchart is especially applicable tothe corded stylus 3910 as shown in FIG. 39C. Unless a causalrelationship is noted, the present invention does not limit executionsequences of any two of the steps as shown in FIG. 41C. Because thecorded stylus 3910 as shown in FIG. 39C comprises the fourth switch 3940and the fourth component 3950, the flowchart further comprises steps4126 and 4128.

Step 4126: selectively receiving the second preamble code by a fourthcomponent which is connected in parallel with the second component. Theselectively receiving is carried out by the fourth switch 3940 as shownin FIG. 39C.

Step 4128: selectively transmitting the second preamble code by thefourth component to a tip section. The selective transmitting is alsocarried out by the fourth switch 3940 as shown in FIG. 39C. The steps4110, 4120, 4126 and 4128 may be being performed concurrently.

Please refer to FIG. 42, which depicts a flowchart diagram applicable toa touch sensitive processing apparatus 130 according to an embodiment ofthe present invention. The flowchart may be applicable to the touchsensitive processing apparatus 130 as shown in FIG. 40 for controlling acorded stylus 3910 as shown in FIGS. 41A-41C. For instance, theflowchart may be implemented as instructions for being executed by theembedded processor 4040 of the touch sensitive processing apparatus 130.Unless a causal relationship is noted, the present invention does notlimit execution sequences of any two of the steps as shown in FIG. 42.The steps 3630, 3640, 3660 and 3680 included in this flowchart arealready explained in the embodiment as shown in FIGS. 36A and 36B.

Step 4210: transmitting a first preamble code according to a first PNcode to a first circuit of a stylus. For example, the first preamblecode is generated by the embedded processor 4040, processed by thedriving circuit 3420, transmitted by the stylus interface 4010 to thesignal circuit 3911.

Step 4220: transmitting a second preamble code according to a second PNcode to a second circuit of the stylus. For example, the second preamblecode is generated by the embedded processor 4040, processed by thedriving circuit 3420, transmitted by the stylus interface 4010 to thesignal circuit 3912. The steps 4210 and 4220 may be being executedconcurrently.

Optional step 4290: calculating a switch status of the stylus accordingto signal strength ratio of the first part and the second part of theelectrical signals.

Please refer to FIG. 43, which depicts a flowchart diagram applicable toa touch sensitive processing apparatus 130 according to an embodiment ofthe present invention. The flowchart may be applicable to the touchsensitive processing apparatus 130 as shown in FIG. 40 for controlling acorded stylus 3910 as shown in FIGS. 41A-41C. For instance, theflowchart may be implemented as instructions for being executed by theembedded processor 4040 of the touch sensitive processing apparatus 130.Unless a causal relationship is noted, the present invention does notlimit execution sequences of any two of the steps as shown in FIG. 43.The step 3880 is already explained in the embodiment as shown in FIGS.38A and 38B. Besides, the optional step 4290 is also explained in theembodiment as shown in FIG. 42.

Step 4310: transmitting a first preamble code according to a first PNcode to a first circuit of a stylus in a first time period.

Step 4320: receiving electrical signals via electrodes of a touch panelin the first time period.

Step 4330: despreading the first preamble code of electrical signalsreceived in the first time period in accordance with the first PN code.

Step 4340: transmitting a second preamble code according to a second PNcode to a second circuit of the stylus in a second time period. Thefirst time period may be completely separated from the second timeperiod. Alternatively, part of the second time period may be concurrentwith part of the first time period.

Step 4350: receiving electrical signals via electrodes of a touch panelin the second time period.

Step 4360: despreading the second preamble code of electrical signalsreceived in the second time period in accordance with the second PNcode.

Please refer to FIG. 44, which depicts a flowchart diagram applicable toa touch sensitive processing apparatus 130 according to an embodiment ofthe present invention. The flowchart may be applicable to the touchsensitive processing apparatus 130 as shown in FIG. 40 for controlling acorded stylus 3910 as shown in FIGS. 41A-41C. For instance, theflowchart may be implemented as instructions for being executed by theembedded processor 4040 of the touch sensitive processing apparatus 130.Unless a causal relationship is noted, the present invention does notlimit execution sequences of any two of the steps as shown in FIG. 44.The steps 4320 and 4350 are explained in the embodiment as shown in FIG.43. The step 3880 is already explained in the embodiment as shown inFIGS. 38A and 38B. Besides, the optional step 4290 is also explained inthe embodiment as shown in FIG. 42.

Step 4410: transmitting a first preamble code according to a PN code toa first circuit of a stylus in a first time period.

Step 4430: despreading the first preamble code of electrical signalsreceived in the first time period in accordance with the PN code.

Step 4440: transmitting a second preamble code according to the PN codeto a second circuit of the stylus in a second time period.

Step 4460: despreading the second preamble code of electrical signalsreceived in the second time period in accordance with the PN code.

One object of the present invention is to provide a stylus fortransmitting electrical signals carrying pressure information,comprising: a first component with variable impedance reflecting apressure, wherein the first component is configured for receiving firstsignals encoded by a first pseudo-random number (PN) code; a secondcomponent with fixed impedance, wherein the second component isconfigured for receiving second signals encoded by a second PN code; anda conductive tip section configured for: receiving, simultaneously, thefirst signals from the first component and the second signals from thesecond component; and transmitting electrical signals which is composedof the first signals and the second signals, wherein the first PN codeis orthogonal to the second PN code.

In one embodiment, in order to provide the first PN code and the secondPN code onboard the stylus, the stylus further comprises a controller,configured for: generating the first signals according to the first PNcode; generating the second signals according the second PN code;transmitting the first signals to the first component; and transmittingthe second signals to the second component.

In one embodiment, in order to transmit status of onboard sensor of thestylus, the stylus further comprises: at least one onboard sensorcoupled to the controller. The controller is further configured for:generating data codes according to status of the at least one onboardsensor; generating first data codes according to the data codes and thefirst PN code; and transmitting the first data codes to the firstcomponent. The first component is further configured for receiving thefirst data codes from the controller. The conductive tip section isfurther configured for: receiving the first data codes from the firstcomponent; and transmitting the first data codes.

In one embodiment, in order to transmit status of onboard sensor of thestylus, the stylus further comprises: at least one onboard sensorcoupled to the controller. The controller is further configured for:generating data codes according to status of the at least one onboardsensor; generating second data codes according to the data codes and thesecond PN code; and transmitting the second data codes to the secondcomponent. The second component is further configured for receiving thesecond data codes from the controller. The conductive tip section isfurther configured for: receiving the second data codes from the secondcomponent; and transmitting the second data codes.

In one embodiment, in order to synchronize with receiving procedure of atouch sensitive processing apparatus of a touch panel, the controller isfurther configured for: receiving a synchronization signal from anelectronic device; and after the synchronization signal is received,executing the generating steps and the transmitting steps.

In one embodiment, in order to synchronize with receiving procedure ofthe touch sensitive processing apparatus of the touch panel where thestylus touches or approximates, the controller is coupled to theconductive tip section for receiving the synchronization signal which isbeing transmitted from electrodes of a touch panel of the electronicdevice.

In one embodiment, in order to prevent conflicts of PN codes whenmultiple styli operate with one touch panel, the stylus furthercomprises a human-machine interface for user's input of PN codes,wherein the controller is further configured for receiving a settinginstruction from the human-machine interface for designating a set ofthe first PN code and the second PN code.

In one embodiment, in order to provide PN code setting information touser, the stylus further comprises at least one of following devicecoupled to the controller for indicating a set of the first PN code andthe second PN code: a visual indicator; and an audio indicator.

In one embodiment, in order to provide a wire connection between thecorded or tethered stylus and a touch sensitive processing apparatus,the stylus further comprises: a first signal circuit, coupled to thefirst component and a touch sensitive processing apparatus, configuredfor propagating the first signals from the touch sensitive processingapparatus to the first component; and a second signal circuit, coupledto the second component and the touch sensitive processing apparatus,configured for propagating the second signals from the touch sensitiveprocessing apparatus to the second component.

In one embodiment, in order to provide a switch status to a touchsensitive processing apparatus, the stylus further comprises a thirdswitch configured for receiving the first signals; and a third componentwith fixed impedance, coupled to the third switch and the conductive tipsection, wherein the third switch is selectively being opened or closed,the first signals are propagated through the third switch and the thirdcomponent to the conductive tip section when the third switch is beingclosed.

In one embodiment, in order to provide a switch status to a touchsensitive processing apparatus, the stylus further comprises a fourthswitch configured for receiving the second signals; and a fourthcomponent with fixed impedance, coupled to the third switch and theconductive tip section, wherein the fourth switch is selectively beingopened or closed, the second signals are propagated through the fourthswitch and the fourth component to the conductive tip section when thefourth switch is being closed.

One object of the present invention is to provide a method fortransmitting electrical signals carrying pressure information from astylus, comprising: receiving, by a first component with variableimpedance reflecting a pressure, first signals encoded by a first PNcode; receiving, by a second component with fixed impedance, secondsignals encoded by a second PN code; receiving, simultaneously, thefirst signals from the first component and the second signals from thesecond component by a conductive tip section; and transmittingelectrical signals which is composed of the first signals and the secondsignals by the conductive tip section, wherein the first PN code isorthogonal to the second PN code.

In one embodiment, in order to provide the first PN code and the secondPN code onboard the stylus, the method further comprises: generating thefirst signals according to the first PN code; generating the secondsignals according the second PN code; transmitting the first signals tothe first component; and transmitting the second signals to the secondcomponent.

In one embodiment, in order to transmit status of onboard sensor of thestylus, the method further comprises: generating data codes according tostatus of at least one onboard sensor; generating first data codesaccording to the data codes and the first PN code; transmitting thefirst data codes to the first component; transmitting, by the firstcomponent, the first data codes to the conductive tip section; andtransmitting, by the conductive tip section, the first data codes.

In one embodiment, in order to transmit status of onboard sensor of thestylus, the method further comprises: generating data codes according tostatus of at least one onboard sensor; generating second data codesaccording to the data codes and the second PN code; transmitting thesecond data codes to the second component; transmitting, by the secondcomponent, the second data codes to the conductive tip section; andtransmitting, by the conductive tip section, the first data codes.

In one embodiment, in order to synchronize with receiving procedure of atouch sensitive processing apparatus of a touch panel, the method isfurther configured for: receiving a synchronization signal from anelectronic device; and after the synchronization signal is received,executing the generating steps and the transmitting steps.

In one embodiment, in order to synchronize with receiving procedure ofthe touch sensitive processing apparatus of the touch panel where thestylus touches or approximates, the synchronization signal which isbeing transmitted from electrodes of a touch panel of the electronicdevice to the conductive tip section.

In one embodiment, in order to prevent conflicts of PN codes whenmultiple styli operate with one touch panel, the method furthercomprises: receiving a setting instruction from a human-machineinterface of the stylus for designating a set of the first PN code andthe second PN code.

In one embodiment, in order to provide PN code setting information touser, the method further comprises at least one of following steps:having a visual indicator of the stylus indicating a set of the first PNcode and the second PN code; and having an audio indicator of the stylusindicating the set of the first PN code and the second PN code.

In one embodiment, in order to provide a wire connection between thecorded or tethered stylus and a touch sensitive processing apparatus,the method further comprises: receiving, by a first signal circuit, thefirst signals from a touch sensitive processing apparatus; propagating,by the first signal circuit, the first signals to the first component;receiving, by a second signal circuit, the second signals from the touchsensitive processing apparatus; and propagating, by the second signalcircuit, the second signals to the second component.

In one embodiment, in order to provide a switch status to a touchsensitive processing apparatus, the method further comprises:selectively receiving, by a third component with fixed impedance, thefirst signals; and selectively transmitting, by the third component, thefirst signals to the conductive tip section.

In one embodiment, in order to provide a switch status to a touchsensitive processing apparatus, the method further comprises:selectively receiving, by a fourth component with fixed impedance, thesecond signals; and selectively transmitting, by the fourth component,the second signals to the conductive tip section.

One object of the present invention is to provide a touch sensitiveprocessing apparatus for receiving electrical signals carrying pressureinformation transmitted from a first stylus, comprising: a sensingcircuit, configured for receiving the electrical signals via electrodesof a touch panel; and a processor, coupled to the sensing circuit,configured for: despreading a first preamble code of the receivedelectrical signals in accordance with a first pseudo-random number (PN)code; despreading a second preamble code of the received electricalsignals in accordance with a second PN code; and calculating thepressure information according to a first signal strength ratio of afirst part of the received electrical signal and a second part of thereceived electrical signal, wherein the first part comprises the firstpreamble code and the second part comprises the second preamble code,wherein the first PN code is orthogonal to the second PN code.

In one embodiment, in order to trigger the stylus for transmittingelectrical signals synchronously, the touch sensitive processingapparatus further comprises a driving circuit, coupled to the electrodesof the touch panel, wherein the processor is further configured forhaving the driving circuit to transmit a beacon signal via theelectrodes of the touch panel before the receiving step is beingexecuted.

In one embodiment, in order to receive status of sensor onboard thestylus, the processor is further configured for: decoding first datacodes of the received electrical signal in accordance with the first PNcode, wherein the first data codes represents status of at least oneonboard sensor of the first stylus.

In one embodiment, in order to receive status of sensor onboard thestylus, the processor is further configured for: decoding second datacodes of the received electrical signal in accordance with the second PNcode, wherein the second data codes represents status of at least oneonboard sensor of the first stylus.

In one embodiment, in order to correctly receive status of sensoronboard the stylus, the processor is further configured for: decodingfirst data codes of the received electrical signal in accordance withthe first PN code; decoding second data codes of the received electricalsignal in accordance with the second PN code; and determining data codesif the first data codes and the second data codes are the same, whereinthe data codes represents status of at least one onboard sensor of thefirst stylus.

In one embodiment, in order to receive more smooth and averaged pressureinformation in a longer transmission, the first part further comprisesthe first data codes and the second part further comprises the seconddata codes.

In one embodiment, in order to synchronize with the transmission of thestylus more quickly, the processor is further configured for: couplingat least two of second electrodes of the touch panel as asynchronization channel, wherein the despreading steps of the firstpreamble code and the second preamble code are being executed on thereceived electrical signals of the synchronization channel to retrieve afirst synchronization information and a second synchronizationinformation, respectively, wherein the second electrodes are arranged inparallel to each other.

In one embodiment, in order to correctly and quickly receive status ofsensor onboard the stylus by utilizing synchronization information, theprocessor is further configured for: decoding first data codes of thereceived electrical signal from at least one of first electrodes of thetouch panel in accordance with the first PN code and the firstsynchronization information; decoding second data codes of the receivedelectrical signal from at least one of the first electrodes of the touchpanel in accordance with the second PN code and the secondsynchronization information; and determining data codes if the firstdata codes and the second data codes are the same, wherein the datacodes represents status of at least one onboard sensor of the firststylus, wherein the first electrodes are arranged in parallel to eachother, and the first electrodes intersect with the second electrodes.

In one embodiment, in order to concurrently receive electrical signalsfrom multiple styli, the processor is further configured for:despreading a third preamble code of the received electrical signals inaccordance with a third PN code; despreading a fourth preamble code ofthe received electrical signals in accordance with a fourth PN code; andcalculating a pressure information of a second stylus according to asecond signal strength ratio of a third part of the received electricalsignal and a fourth part of the received electrical signal, wherein thethird part comprises the third preamble code and the fourth partcomprises the fourth preamble code, wherein the first PN code, thesecond PN code, the third PN code and the fourth PN code are orthogonalto each other.

In one embodiment, in order to provide a wire connection between acorded or tethered stylus and the touch sensitive processing apparatus,the touch sensitive processing apparatus further comprises: a stylusinterface, coupled to a first signal circuit and a second signal circuitof the first stylus, wherein the processor, coupled to the stylusinterface, is further configured for: generating the first preamble codein accordance with the first PN code; generating the second preamblecode in accordance with the second PN code; and transmitting the firstpreamble code and the second preamble code to the first signal circuitand the second signal circuit via the stylus interface, respectively.

In one embodiment, in order to receive status of a switch of the stylus,the processor is further configured for: calculating a switch status ofthe first stylus according to the first signal strength ratio of thefirst part of the received electrical signal and the second part of thereceived electrical signal.

In one embodiment, in order to concurrently connect with multiple cordedor tethered styli, the stylus interface is further coupled to a thirdsignal circuit and a fourth signal circuit of a second stylus. Theprocessor, coupled to the stylus interface, is further configured for:generating a third preamble code in accordance with a third PN code;generating a fourth preamble code in accordance with a fourth PN code;and transmitting the third preamble code and the fourth preamble code tothe third signal circuit and the fourth signal circuit via the stylusinterface, respectively, wherein the first PN code, the second PN code,the third PN code and the fourth PN code are orthogonal to each other.

One object of the present invention is to provide a method for receivingelectrical signals carrying pressure information transmitted from afirst stylus, comprising: receiving the electrical signals viaelectrodes of a touch panel; despreading a first preamble code of thereceived electrical signals in accordance with a first PN code;despreading a second preamble code of the received electrical signals inaccordance with a second PN code; and calculating the pressureinformation according to a first signal strength ratio of a first partof the received electrical signal and a second part of the receivedelectrical signal, wherein the first part comprises the first preamblecode and the second part comprises the second preamble code, wherein thefirst PN code is orthogonal to the second PN code.

In one embodiment, in order to trigger the stylus for transmittingelectrical signals synchronously, the method further comprises:transmitting a beacon signal via the electrodes of the touch panelbefore the receiving step is being executed.

In one embodiment, in order to receive status of sensor onboard thestylus, the method further comprises: decoding first data codes of thereceived electrical signal in accordance with the first PN code, whereinthe first data codes represents status of at least one onboard sensor ofthe first stylus.

In one embodiment, in order to receive status of sensor onboard thestylus, the method further comprises: decoding second data codes of thereceived electrical signal in accordance with the second PN code,wherein the second data codes represents status of at least one onboardsensor of the first stylus.

In one embodiment, in order to correctly receive status of sensoronboard the stylus, the method further comprises: decoding first datacodes of the received electrical signal in accordance with the first PNcode; decoding second data codes of the received electrical signal inaccordance with the second PN code; and determining data codes if thefirst data codes and the second data codes are the same, wherein thedata codes represents status of at least one onboard sensor of the firststylus.

In one embodiment, in order to receive more smooth and averaged pressureinformation in a longer transmission, the first part further comprisesthe first data codes and the second part further comprises the seconddata codes.

In one embodiment, in order to synchronize with the transmission of thestylus more quickly, the method further comprises: coupling at least twoof second electrodes of the touch panel as a synchronization channel,wherein the despreading steps of the first preamble code and the secondpreamble code are being executed on the received electrical signals ofthe synchronization channel to retrieve a first synchronizationinformation and a second synchronization information, respectively,wherein the second electrodes are arranged in parallel to each other.

In one embodiment, in order to correctly and quickly receive status ofsensor onboard the stylus by utilizing synchronization information, themethod further comprises: decoding first data codes of the receivedelectrical signal from at least one of first electrodes of the touchpanel in accordance with the first PN code and the first synchronizationinformation; decoding second data codes of the received electricalsignal from at least one of the first electrodes of the touch panel inaccordance with the second PN code and the second synchronizationinformation; and determining data codes if the first data codes and thesecond data codes are the same, wherein the data codes represents statusof at least one onboard sensor of the first stylus, wherein the firstelectrodes are arranged in parallel to each other, and the firstelectrodes intersect with the second electrodes.

In one embodiment, in order to concurrently receive electrical signalsfrom multiple styli, the method further comprises: despreading a thirdpreamble code of the received electrical signals in accordance with athird PN code; despreading a fourth preamble code of the receivedelectrical signals in accordance with a fourth PN code; and calculatinga pressure information of a second stylus according to a second signalstrength ratio of a third part of the received electrical signal and afourth part of the received electrical signal, wherein the third partcomprises the third preamble code and the fourth part comprises thefourth preamble code, wherein the first PN code, the second PN code, thethird PN code and the fourth PN code are orthogonal to each other.

In one embodiment, in order to provide a wire connection between acorded or tethered stylus and the touch sensitive processing apparatus,the method further comprises: generating the first preamble code inaccordance with the first PN code; generating the second preamble codein accordance with the second PN code; and transmitting the firstpreamble code and the second preamble code to a first signal circuit anda second signal circuit of the first stylus, respectively.

In one embodiment, in order to receive status of a switch of the stylus,the method further comprises: calculating a switch status of the firststylus according to the first signal strength ratio of the first part ofthe received electrical signal and the second part of the receivedelectrical signal.

In one embodiment, in order to concurrently connect with multiple cordedor tethered styli, the method further comprises: generating a thirdpreamble code in accordance with a third PN code; generating a fourthpreamble code in accordance with a fourth PN code; and transmitting thethird preamble code and the fourth preamble code to a third signalcircuit and a fourth signal circuit of a second stylus, respectively,wherein the first PN code, the second PN code, the third PN code and thefourth PN code are orthogonal to each other.

One object of the present invention is to provide a touch system, whichcomprising: a touch panel; a first stylus; and a touch sensitiveprocessing apparatus for receiving electrical signals carrying pressureinformation transmitted from the first stylus. The touch sensitiveprocessing apparatus comprises: a sensing circuit, configured forreceiving the electrical signals via electrodes of the touch panel; anda processor, coupled to the sensing circuit, configured for: despreadinga first preamble code of the received electrical signals in accordancewith a first PN code; despreading a second preamble code of the receivedelectrical signals in accordance with a second PN code; and calculatingthe pressure information according to a first signal strength ratio of afirst part of the received electrical signal and a second part of thereceived electrical signal, wherein the first part comprises the firstpreamble code and the second part comprises the second preamble code,wherein the first PN code is orthogonal to the second PN code.

In one embodiment, the first stylus further comprises: a first componentwith variable impedance reflecting a pressure, wherein the firstcomponent is configured for receiving first signals encoded by the firstPN code; a second component with fixed impedance, wherein the secondcomponent is configured for receiving second signals encoded by thesecond PN code; and a conductive tip section configured for: receiving,simultaneously, the first signals from the first component and thesecond signals from the second component; and transmitting theelectrical signals which is composed of the first signals and the secondsignals.

One object of the present invention is to provide a stylus fortransmitting electrical signals carrying pressure information,comprising: a first component with variable impedance reflecting apressure, wherein the first component is configured for receiving firstsignals encoded by a pseudo-random number (PN) code in a first timeperiod; a second component with fixed impedance, wherein the secondcomponent is configured for receiving second signals encoded by the PNcode in a second time period; and a conductive tip section configuredfor: receiving the first signals from the first component in the firsttime period; receiving the second signals from the second component inthe second time period; transmitting electrical signals which iscomposed of the first signals in the first time period; and transmittingelectrical signals which is composed of the second signals in the secondtime period.

In one embodiment, in order to provide the PN code onboard the stylus,the stylus further comprises a controller, configured for: generatingthe first signals according to the PN code; generating the secondsignals according the PN code; transmitting the first signals to thefirst component; and transmitting the second signals to the secondcomponent.

In one embodiment, in order to transmit status of onboard sensor of thestylus, the stylus further comprises: at least one onboard sensorcoupled to the controller, wherein the controller is further configuredfor: generating data codes according to status of the at least oneonboard sensor; generating first data codes according to the data codesand the PN code; and transmitting the first data codes to the firstcomponent. The first component is further configured for receiving thefirst data codes from the controller in the first time period. Theconductive tip section is further configured for in the first timeperiod: receiving the first data codes from the first component; andtransmitting the first data codes.

In one embodiment, in order to transmit status of onboard sensor of thestylus, the stylus further comprises: at least one onboard sensorcoupled to the controller, wherein the controller is further configuredfor: generating data codes according to status of the at least oneonboard sensor; generating second data codes according to the data codesand the PN code; and transmitting the second data codes to the secondcomponent. The second component is further configured for receiving thesecond data codes from the controller in the second time period. Theconductive tip section is further configured for in the second timeperiod: receiving the second data codes from the second component; andtransmitting the second data codes.

In one embodiment, in order to synchronize with receiving procedure of atouch sensitive processing apparatus of a touch panel, the controller isfurther configured for: receiving a synchronization signal from anelectronic device; and after the synchronization signal is received,executing the generating steps and the transmitting steps.

In one embodiment, in order to synchronize with receiving procedure ofthe touch sensitive processing apparatus of the touch panel where thestylus touches or approximates, the controller is coupled to theconductive tip section for receiving the synchronization signal which isbeing transmitted from electrodes of a touch panel of the electronicdevice.

In one embodiment, in order to prevent conflicts of PN codes whenmultiple styli operate with one touch panel, the stylus furthercomprises a human-machine interface for user's input of PN codes,wherein the controller is further configured for receiving a settinginstruction from the human-machine interface for designating the PNcode.

In one embodiment, in order to provide PN code setting information touser, the stylus further comprises at least one of following devicecoupled to the controller for indicating the PN code: a visualindicator; and an audio indicator.

In one embodiment, in order to provide a wire connection between thecorded or tethered stylus and a touch sensitive processing apparatus,the stylus further comprises: a first signal circuit, coupled to thefirst component and a touch sensitive processing apparatus, configuredfor propagating the first signals from the touch sensitive processingapparatus to the first component; and a second signal circuit, coupledto the second component and the touch sensitive processing apparatus,configured for propagating the second signals from the touch sensitiveprocessing apparatus to the second component.

In order to provide a switch status to a touch sensitive processingapparatus, the stylus further comprises: a third switch configured forreceiving the first signals in the first time period; and a thirdcomponent with fixed impedance, coupled to the third switch and theconductive tip section, wherein the third switch is selectively beingopened or closed, the first signals are propagated through the thirdswitch and the third component to the conductive tip section when thethird switch is being closed.

In order to provide a switch status to a touch sensitive processingapparatus, the stylus further comprises: a fourth switch configured forreceiving the second signals in the second time period; and a fourthcomponent with fixed impedance, coupled to the third switch and theconductive tip section, wherein the fourth switch is selectively beingopened or closed, the second signals are propagated through the fourthswitch and the fourth component to the conductive tip section when thefourth switch is being closed.

One object of the present invention is to provide a method fortransmitting electrical signals carrying pressure information from astylus, comprising: receiving, by a first component with variableimpedance reflecting a pressure, first signals encoded by a PN code in afirst time period; receiving, by a second component with fixedimpedance, second signals encoded by the PN code in a second timeperiod; receiving the first signals from the first component by aconductive tip section in the first time period; receiving the secondsignals from the second component by the conductive tip section in thesecond time period; and transmitting electrical signals which iscomposed of the first signals in the first time period by the conductivetip section; and transmitting electrical signals which is composed ofthe second signals in the second time period by the conductive tipsection.

In one embodiment, in order to provide the PN code onboard the stylus,the method further comprises: generating the first signals according tothe PN code; generating the second signals according the PN code;transmitting the first signals to the first component; and transmittingthe second signals to the second component.

In one embodiment, in order to transmit status of onboard sensor of thestylus, the method further comprises: generating data codes according tostatus of at least one onboard sensor; generating first data codesaccording to the data codes and the PN code; transmitting the first datacodes to the first component; transmitting, by the first component, thefirst data codes to the conductive tip section; and transmitting, by theconductive tip section, the first data codes.

In one embodiment, in order to transmit status of onboard sensor of thestylus, the method further comprises: generating data codes according tostatus of at least one onboard sensor; generating second data codesaccording to the data codes and the PN code; and transmitting the seconddata codes to the second component; transmitting, by the secondcomponent, the second data codes to the conductive tip section; andtransmitting, by the conductive tip section, the second data codes.

In one embodiment, in order to synchronize with receiving procedure of atouch sensitive processing apparatus of a touch panel, the methodfurther comprises: receiving a synchronization signal from an electronicdevice; and after the synchronization signal is received, executing thegenerating steps and the transmitting steps.

In one embodiment, in order to synchronize with receiving procedure ofthe touch sensitive processing apparatus of the touch panel where thestylus touches or approximates, wherein the synchronization signal whichis being transmitted from electrodes of a touch panel of the electronicdevice to the conductive tip section.

In one embodiment, in order to prevent conflicts of PN codes whenmultiple styli operate with one touch panel, the method furthercomprises: receiving a setting instruction from a human-machineinterface of the stylus for designating the PN code.

In one embodiment, in order to provide PN code setting information touser, the method further comprises at least one of following steps:having a visual indicator of the stylus indicating the PN code; andhaving an audio indicator of the stylus indicating the PN code.

In one embodiment, in order to provide a wire connection between thecorded or tethered stylus and a touch sensitive processing apparatus,the method futher comprises: receiving, by a first signal circuit, thefirst signals from a touch sensitive processing apparatus; propagating,by the first signal circuit, the first signals to the first component;receiving, by a second signal circuit, the second signals from the touchsensitive processing apparatus; and propagating, by the second signalcircuit, the second signals to the second component.

In one embodiment, in order to provide a switch status to a touchsensitive processing apparatus, the method further comprises:selectively receiving, by a third component with fixed impedance, thefirst signals; and selectively transmitting, by the third component, thefirst signals to the conductive tip section.

In one embodiment, in order to provide a switch status to a touchsensitive processing apparatus, the method further comprises:selectively receiving, by a fourth component with fixed impedance, thesecond signals; and selectively transmitting, by the fourth component,the second signals to the conductive tip section.

One object of the present invention is to provide a touch sensitiveprocessing apparatus for receiving electrical signals carrying pressureinformation transmitted from a first stylus, comprising: a sensingcircuit, configured for receiving the electrical signals via electrodesof a touch panel; and a processor, coupled to the sensing circuit,configured for: despreading a first preamble code of the receivedelectrical signals in accordance with a pseudo-random number (PN) codein a first time period; despreading a second preamble code of thereceived electrical signals in accordance with the PN code in a secondtime period; and calculating the pressure information according to afirst signal strength ratio of a first part of the received electricalsignal and a second part of the received electrical signal, wherein thefirst part comprises the first preamble code and the second partcomprises the second preamble code.

In one embodiment, in order to trigger the stylus for transmittingelectrical signals synchronously, the touch sensitive apparatus furthercomprises: a driving circuit, coupled to the electrodes of the touchpanel, wherein the processor is further configured for having thedriving circuit to transmit a beacon signal via the electrodes of thetouch panel before the receiving steps are being executed.

In one embodiment, in order to receive status of sensor onboard thestylus, the processor is further configured for: decoding first datacodes of the electrical signal received in the first time period inaccordance with the PN code, wherein the data codes represents status ofat least one onboard sensor of the first stylus.

In one embodiment, in order to receive status of sensor onboard thestylus, the processor is further configured for: decoding second datacodes of the electrical signal received in the second time period inaccordance with the PN code, wherein the data codes represents status ofat least one onboard sensor of the first stylus.

In one embodiment, in order to correctly receive status of sensoronboard the stylus, the processor is further configured for: decodingfirst data codes of the electrical signal received in the first timeperiod in accordance with the PN code; decoding second data codes of theelectrical signal received in the second time period in accordance withthe PN code; and determining data codes if the first data codes and thesecond data codes are the same, wherein the data codes represents statusof at least one onboard sensor of the first stylus.

In one embodiment, in order to receive more smooth and averaged pressureinformation in a longer transmission, the first part further comprisesthe first data codes and the second part further comprises the seconddata codes.

In one embodiment, in order to synchronize with the transmission of thestylus more quickly, the processor is further configured for: couplingat least two of second electrodes of the touch panel as asynchronization channel, wherein the despreading steps of the firstpreamble code and the second preamble code are being executed on thereceived electrical signals of the synchronization channel to retrieve afirst synchronization information and a second synchronizationinformation, respectively, wherein the second electrodes are arranged inparallel to each other.

In one embodiment, in order to correctly and quickly receive status ofsensor onboard the stylus by utilizing synchronization information, theprocessor is further configured for: decoding first data codes of thereceived electrical signal from at least one of first electrodes of thetouch panel in accordance with the PN code and the first synchronizationinformation; decoding second data codes of the received electricalsignal from at least one of the first electrodes of the touch panel inaccordance with the PN code and the second synchronization information;and determining data codes if the first data codes and the second datacodes are the same, wherein the data codes represents status of at leastone onboard sensor of the first stylus, wherein the first electrodes arearranged in parallel to each other, and the first electrodes intersectwith the second electrodes.

In one embodiment, in order to receive electrical signals from multiplestyli, the processor is further configured for: despreading a thirdpreamble code of the electrical signals received in a third time periodin accordance with a second PN code; despreading a fourth preamble codeof the electrical signals received in a fourth time period in accordancewith the second PN code; and calculating a pressure information of asecond stylus according to a second signal strength ratio of a thirdpart of the received electrical signal and a fourth part of the receivedelectrical signal, wherein the third part comprises the third preamblecode and the fourth part comprises the fourth preamble code, wherein thePN code and the second PN code are orthogonal to each other, whereinpart of the third time period is overlapped with part of the first timeperiod or part of the second time period.

In one embodiment, in order to provide a wire connection between acorded or tethered stylus and the touch sensitive processing apparatus,the touch sensitive processing apparatus further comprises: a stylusinterface, coupled to a first signal circuit and a second signal circuitof the first stylus, wherein the processor, coupled to the stylusinterface, is further configured for: generating the first preamble codein accordance with the PN code; generating the second preamble code inaccordance with the PN code; transmitting the first preamble code to thefirst signal circuit via the stylus interface in the first time period;and transmitting the second preamble code to the second signal circuitvia the stylus interface in the second time period.

In one embodiment, in order to receive status of a switch of the stylus,the processor is further configured for: calculating a switch status ofthe first stylus according to the first signal strength ratio of thefirst part of the received electrical signal and the second part of thereceived electrical signal.

In one embodiment, in order to concurrently connect with multipl styli,the stylus interface is further coupled to a third signal circuit and afourth signal circuit of a second stylus. The processor, coupled to thestylus interface, is further configured for: generating a third preamblecode in accordance with a second PN code in a third time period;generating a fourth preamble code in accordance with the second PN codein a fourth time period; transmitting the third preamble code to thethird signal circuit in the third time period via the stylus interface;and transmitting the fourth preamble code to the fourth signal circuitin the fourth time period via the stylus interface, respectively,wherein the PN code and the second PN code are orthogonal to each other,wherein part of the third time period is overlapped with part of thefirst time period or part of the second time period.

One object of the present invention is to provide a method for receivingelectrical signals carrying pressure information transmitted from afirst stylus, comprising: receiving the electrical signals viaelectrodes of a touch panel; despreading a first preamble code of theelectrical signals received in a first time period in accordance with aPN code; despreading a second preamble code of the electrical signalsreceived in a second time period in accordance with the PN code; andcalculating the pressure information according to a first signalstrength ratio of a first part of the received electrical signal and asecond part of the received electrical signal, wherein the first partcomprises the first preamble code and the second part comprises thesecond preamble code.

In one embodiment, in order to trigger the stylus for transmittingelectrical signals synchronously, the method further comprisestransmitting a beacon signal via the electrodes of the touch panelbefore the receiving step is being executed.

In one embodiment, in order to receive status of sensor onboard thestylus, the method further comprises: decoding first data codes of theelectrical signal received in the first time period in accordance withthe PN code, wherein the first data codes represents status of at leastone onboard sensor of the first stylus.

In one embodiment, in order to receive status of sensor onboard thestylus, the method further comprises: decoding second data codes of theelectrical signal received in the second time period in accordance withthe PN code, wherein the second data codes represents status of at leastone onboard sensor of the first stylus.

In one embodiment, in order to correctly receive status of sensoronboard the stylus, the method further comprises: decoding first datacodes of the electrical signal received in the first time period inaccordance with the PN code; decoding second data codes of theelectrical signal received in the second time period in accordance withthe PN code; and determining data codes if the first data codes and thesecond data codes are the same, wherein the data codes represents statusof at least one onboard sensor of the first stylus.

In one embodiment, in order to receive more smooth and averaged pressureinformation in a longer transmission, the first part further comprisesthe first data codes and the second part further comprises the seconddata codes.

In one embodiment, in order to synchronize with the transmission of thestylus more quickly, the method further comprises: coupling at least twoof second electrodes of the touch panel as a synchronization channel,wherein the despreading steps of the first preamble code and the secondpreamble code are being executed on the received electrical signals ofthe synchronization channel to retrieve a first synchronizationinformation and a second synchronization information, respectively,wherein the second electrodes are arranged in parallel to each other.

In one embodiment, in order to correctly and quickly receive status ofsensor onboard the stylus by utilizing synchronization information, themethod further comprises: decoding first data codes of the receivedelectrical signal from at least one of first electrodes of the touchpanel in accordance with the PN code and the first synchronizationinformation; decoding second data codes of the received electricalsignal from at least one of the first electrodes of the touch panel inaccordance with the PN code and the second synchronization information;and determining data codes if the first data codes and the second datacodes are the same, wherein the data codes represents status of at leastone onboard sensor of the first stylus, wherein the first electrodes arearranged in parallel to each other, and the first electrodes intersectwith the second electrodes.

In one embodiment, in order to concurrently receive electrical signalsfrom multiple styli, the method further comprises: despreading a thirdpreamble code of the electrical signals received in a third time periodin accordance with a second PN code; despreading a fourth preamble codeof the electrical signals received in a fourth time period in accordancewith the second PN code; and calculating a pressure information of asecond stylus according to a second signal strength ratio of a thirdpart of the received electrical signal and a fourth part of the receivedelectrical signal, wherein the third part comprises the third preamblecode and the fourth part comprises the fourth preamble code, wherein thePN code and the second PN code are orthogonal to each other, whereinpart of the third time period is overlapped with part of the first timeperiod or part of the second time period.

In one embodiment, in order to provide a wire connection between acorded or tethered stylus and the touch sensitive processing apparatus,the method further comprises: generating the first preamble code inaccordance with the PN code in the first time period; generating thesecond preamble code in accordance with the PN code in the second timeperiod; transmitting the first preamble code to a first signal circuitof the first stylus in the first time period; and transmitting thesecond preamble code to a second signal circuit of the first stylus inthe second time period.

In one embodiment, in order to receive status of a switch of the stylus,the method further comprises: calculating a switch status of the firststylus according to the first signal strength ratio of the first part ofthe received electrical signal and the second part of the receivedelectrical signal.

In one embodiment, in order to concurrently connect with multiple cordedor tethered styli, the method further comprises: generating a thirdpreamble code in accordance with a second PN code in a third timeperiod; generating a fourth preamble code in accordance with the secondPN code in a fourth time period; transmitting the third preamble code toa third signal circuit of a second stylus in the third time period; andtransmitting the fourth preamble code to a fourth signal circuit of thesecond stylus in the fourth time period, wherein the PN code and thesecond PN code are orthogonal to each other, wherein part of the thirdtime period is overlapped with part of the first time period or part ofthe second time period.

One object of the present invention is to provide a touch systemcomprising: a touch panel; a first stylus; and a touch sensitiveprocessing apparatus. The touch sensitive processing apparatus forreceiving electrical signals carrying pressure information transmittedfrom the first stylus, comprising: a sensing circuit, configured forreceiving the electrical signals via electrodes of the touch panel; anda processor, coupled to the sensing circuit, configured for: despreadinga first preamble code of the received electrical signals in accordancewith a PN code in a first time period; despreading a second preamblecode of the received electrical signals in accordance with the PN codein a second time period; and calculating the pressure informationaccording to a first signal strength ratio of a first part of thereceived electrical signal and a second part of the received electricalsignal, wherein the first part comprises the first preamble code and thesecond part comprises the second preamble code.

In one embodiment, the first stylus comprising: a first component withvariable impedance reflecting a pressure, wherein the first component isconfigured for receiving first signals encoded by the PN code in thefirst time period; a second component with fixed impedance, wherein thesecond component is configured for receiving second signals encoded bythe PN code in the second time period; and a conductive tip sectionconfigured for: receiving the first signals from the first component inthe first time period; receiving the second signals from the secondcomponent in the second time period; transmitting electrical signalswhich is composed of the first signals in the first time period; andtransmitting electrical signals which is composed of the second signalsin the second time period.

The above embodiments are only used to illustrate the principles of thepresent invention, and they should not be construed as to limit thepresent invention in any way. The above embodiments can be modified bythose with ordinary skill in the art without departing from the scope ofthe present invention as defined in the following appended claims.

What is claimed is:
 1. A touch sensitive processing apparatus for receiving electrical signals carrying pressure information transmitted from a first stylus, comprising: a sensing circuit, configured for receiving the electrical signals via electrodes of a touch panel; and a processor, coupled to the sensing circuit, configured for: despreading a first preamble code of the received electrical signals in accordance with a pseudo-random number (PN) code in a first time period; despreading a second preamble code of the received electrical signals in accordance with the PN code in a second time period; and calculating the pressure information according to a first signal strength ratio of a first part of the received electrical signal and a second part of the received electrical signal, wherein the first part comprises the first preamble code and the second part comprises the second preamble code.
 2. The touch sensitive processing apparatus of claim 1, further comprising: a driving circuit, coupled to the electrodes of the touch panel, wherein the processor is further configured for having the driving circuit to transmit a beacon signal via the electrodes of the touch panel before the receiving steps are being executed.
 3. The touch sensitive processing apparatus of claim 1, wherein the processor is further configured for: decoding first data codes of the electrical signal received in the first time period in accordance with the PN code, wherein the data codes represents status of at least one onboard sensor of the first stylus.
 4. The touch sensitive processing apparatus of claim 1, wherein the processor is further configured for: decoding second data codes of the electrical signal received in the second time period in accordance with the PN code, wherein the second data codes represents status of at least one onboard sensor of the first stylus.
 5. The touch sensitive processing apparatus of claim 1, wherein the processor is further configured for: decoding first data codes of the electrical signal received in the first time period in accordance with the PN code; decoding second data codes of the electrical signal received in the second time period in accordance with the PN code; and determining data codes if the first data codes and the second data codes are the same, wherein the data codes represents status of at least one onboard sensor of the first stylus.
 6. The touch sensitive processing apparatus of claim 5, wherein the first part further comprises the first data codes and the second part further comprises the second data codes.
 7. The touch sensitive processing apparatus of claim 1, wherein the processor is further configured for: coupling at least two of second electrodes of the touch panel as a synchronization channel, wherein the despreading steps of the first preamble code and the second preamble code are being executed on the received electrical signals of the synchronization channel to retrieve a first synchronization information and a second synchronization information, respectively, wherein the second electrodes are arranged in parallel to each other.
 8. The touch sensitive processing apparatus of claim 7, wherein the processor is further configured for: decoding first data codes of the received electrical signal from at least one of first electrodes of the touch panel in accordance with the PN code and the first synchronization information; decoding second data codes of the received electrical signal from at least one of the first electrodes of the touch panel in accordance with the PN code and the second synchronization information; and determining data codes if the first data codes and the second data codes are the same, wherein the data codes represents status of at least one onboard sensor of the first stylus, wherein the first electrodes are arranged in parallel to each other, and the first electrodes intersect with the second electrodes.
 9. The touch sensitive processing apparatus of claim 1, wherein the processor is further configured for: despreading a third preamble code of the electrical signals received in a third time period in accordance with a second PN code; despreading a fourth preamble code of the electrical signals received in a fourth time period in accordance with the second PN code; and calculating a pressure information of a second stylus according to a second signal strength ratio of a third part of the received electrical signal and a fourth part of the received electrical signal, wherein the third part comprises the third preamble code and the fourth part comprises the fourth preamble code, wherein the PN code and the second PN code are orthogonal to each other, wherein part of the third time period is overlapped with part of the first time period or part of the second time period.
 10. The touch sensitive processing apparatus of claim 1, further comprising: a stylus interface, coupled to a first signal circuit and a second signal circuit of the first stylus, wherein the processor, coupled to the stylus interface, is further configured for: generating the first preamble code in accordance with the PN code; generating the second preamble code in accordance with the PN code; transmitting the first preamble code to the first signal circuit via the stylus interface in the first time period; and transmitting the second preamble code to the second signal circuit via the stylus interface in the second time period.
 11. The touch sensitive processing apparatus of claim 10, wherein the processor is further configured for: calculating a switch status of the first stylus according to the first signal strength ratio of the first part of the received electrical signal and the second part of the received electrical signal.
 12. The touch sensitive processing apparatus of claim 10, wherein the stylus interface is further coupled to a third signal circuit and a fourth signal circuit of a second stylus, wherein the processor, coupled to the stylus interface, is further configured for: generating a third preamble code in accordance with a second PN code in a third time period; generating a fourth preamble code in accordance with the second PN code in a fourth time period; transmitting the third preamble code to the third signal circuit in the third time period via the stylus interface; and transmitting the fourth preamble code to the fourth signal circuit in the fourth time period via the stylus interface, respectively, wherein the PN code and the second PN code are orthogonal to each other, wherein part of the third time period is overlapped with part of the first time period or part of the second time period.
 13. A method for receiving electrical signals carrying pressure information transmitted from a first stylus, comprising: receiving the electrical signals via electrodes of a touch panel; despreading a first preamble code of the electrical signals received in a first time period in accordance with a PN code; despreading a second preamble code of the electrical signals received in a second time period in accordance with the PN code; and calculating the pressure information according to a first signal strength ratio of a first part of the received electrical signal and a second part of the received electrical signal, wherein the first part comprises the first preamble code and the second part comprises the second preamble code.
 14. The method of claim 13, further comprising: transmitting a beacon signal via the electrodes of the touch panel before the receiving step is being executed.
 15. The method of claim 13, further comprising: decoding first data codes of the electrical signal received in the first time period in accordance with the PN code, wherein the first data codes represents status of at least one onboard sensor of the first stylus.
 16. The method of claim 13, further comprising: decoding second data codes of the electrical signal received in the second time period in accordance with the PN code, wherein the second data codes represents status of at least one onboard sensor of the first stylus.
 17. The method of claim 13, further comprising: decoding first data codes of the electrical signal received in the first time period in accordance with the PN code; decoding second data codes of the electrical signal received in the second time period in accordance with the PN code; and determining data codes if the first data codes and the second data codes are the same, wherein the data codes represents status of at least one onboard sensor of the first stylus.
 18. The method of claim 17, wherein the first part further comprises the first data codes and the second part further comprises the second data codes.
 19. The method of claim 13, further comprising: coupling at least two of second electrodes of the touch panel as a synchronization channel, wherein the despreading steps of the first preamble code and the second preamble code are being executed on the received electrical signals of the synchronization channel to retrieve a first synchronization information and a second synchronization information, respectively, wherein the second electrodes are arranged in parallel to each other.
 20. The method of claim 19, further comprising: decoding first data codes of the received electrical signal from at least one of first electrodes of the touch panel in accordance with the PN code and the first synchronization information; decoding second data codes of the received electrical signal from at least one of the first electrodes of the touch panel in accordance with the PN code and the second synchronization information; and determining data codes if the first data codes and the second data codes are the same, wherein the data codes represents status of at least one onboard sensor of the first stylus, wherein the first electrodes are arranged in parallel to each other, and the first electrodes intersect with the second electrodes.
 21. The method of claim 13, further comprising: despreading a third preamble code of the electrical signals received in a third time period in accordance with a second PN code; despreading a fourth preamble code of the electrical signals received in a fourth time period in accordance with the second PN code; and calculating a pressure information of a second stylus according to a second signal strength ratio of a third part of the received electrical signal and a fourth part of the received electrical signal, wherein the third part comprises the third preamble code and the fourth part comprises the fourth preamble code, wherein the PN code and the second PN code are orthogonal to each other, wherein part of the third time period is overlapped with part of the first time period or part of the second time period.
 22. The method of claim 13, further comprising: generating the first preamble code in accordance with the PN code in the first time period; generating the second preamble code in accordance with the PN code in the second time period; transmitting the first preamble code to a first signal circuit of the first stylus in the first time period; and transmitting the second preamble code to a second signal circuit of the first stylus in the second time period.
 23. The method of claim 22, further comprising: calculating a switch status of the first stylus according to the first signal strength ratio of the first part of the received electrical signal and the second part of the received electrical signal.
 24. The method of claim 22, further comprising: generating a third preamble code in accordance with a second PN code in a third time period; generating a fourth preamble code in accordance with the second PN code in a fourth time period; transmitting the third preamble code to a third signal circuit of a second stylus in the third time period; and transmitting the fourth preamble code to a fourth signal circuit of the second stylus in the fourth time period, wherein the PN code and the second PN code are orthogonal to each other, wherein part of the third time period is overlapped with part of the first time period or part of the second time period.
 25. A touch system, comprising: a touch panel; a first stylus; and a touch sensitive processing apparatus for receiving electrical signals carrying pressure information transmitted from the first stylus, comprising: a sensing circuit, configured for receiving the electrical signals via electrodes of the touch panel; and a processor, coupled to the sensing circuit, configured for: despreading a first preamble code of the received electrical signals in accordance with a PN code in a first time period; despreading a second preamble code of the received electrical signals in accordance with the PN code in a second time period; and calculating the pressure information according to a first signal strength ratio of a first part of the received electrical signal and a second part of the received electrical signal, wherein the first part comprises the first preamble code and the second part comprises the second preamble code.
 26. The touch system of claim 25, wherein the first stylus comprising: a first component with variable impedance reflecting a pressure, wherein the first component is configured for receiving first signals encoded by the PN code in the first time period; a second component with fixed impedance, wherein the second component is configured for receiving second signals encoded by the PN code in the second time period; and a conductive tip section configured for: receiving the first signals from the first component in the first time period; receiving the second signals from the second component in the second time period; transmitting electrical signals which is composed of the first signals in the first time period; and transmitting electrical signals which is composed of the second signals in the second time period. 